Segmentation fault C language strcat() - c

#include <stdio.h>
int main() {
char lexer_string[] = "echo Hello %a% %b%";
char temp_variable_name[128] = "...";
int variable_buff = 0;
int check = 0;
int detect_start = 0;
for (int i = 0; i < sizeof(lexer_string); i++) {
// printf("%c\n", lexer_string[i]);
if (lexer_string[i] == '%' && variable_buff == 0) {
check = 1;
variable_buff = 1;
}
if (variable_buff == 1) {
if (lexer_string[i] == '%' && detect_start == 0) {
detect_start = 1;
printf("%%\x20");
}
else if (lexer_string[i] == '%' && detect_start == 1) {
detect_start = 0;
printf(" \%\n");
}
else if (lexer_string[i] != '%') {
printf("%c", lexer_string[i]);
strcat(temp_variable_name, lexer_string[i]);
strcat(temp_variable_name, ' ');
}
}
if (lexer_string[i] == '%' && variable_buff == 1 && check != 1) {
variable_buff = 0;
}
if (lexer_string[i] == '\0') {
printf("Wynik:%s\n", temp_variable_name);
break;
}
check = 0;
}
return 0;
}
This is my simple code, when i use the function strcat() my code stops working. I tried change size of char array's, changed position of function in program (i move them to end but still doesn't work.)

Related

Find index of word in string

I want to write a function which will find index of word in string.
For example if string is
This is word.
my function for string "word" should return number 3.
Note: functions from string.h library and auxiliary strings are not allowed.
How could I do this in C?
I can't think of a solution better than this (though there might be better ones).
#include <stdio.h>
int main() {
char word[] = "This is a word";
int flag = 0, space = 0, pos = -1;
for (int i = 0; word[i] != '\0'; i++) {
if (flag == 1) {
break;
}
for (int j = 0; word[j] != '\0'; j++) {
if (flag == 1) {
break;
}
else if (word[j+1] == '\0' || word[j+2] == '\0' || word[j+3] == '\0') {
break;
}
else {
if (word[j] == 'w' && word[j+1] == 'o' && word[j+2] == 'r' && word[j+3] == 'd') {
flag = 1;
pos = j;
}
}
}
}
for (int i = 0; word[i] != '\0'; i++) {
if (word[i] == ' ' || word[i] == '!' || word[i] == '#') {// And many more symbols
fchars++;
}
else {
break;
}
}
if (flag == 1 && pos-1 > 0 && word[pos-1] == ' ') {
for (int i = 0; i < pos; i++) {
if (word[i] == ' ') {
space++;
}
}
printf("Found at position = %i\n", space+1-fchars);
}
else {
printf("Not found!\n");
}
}
You can split the sentence by space to get the words and then match each word in the sentence with the word you want to match
Please check this modified code:
#include<stdio.h>
int main()
{
char word[] = "word";
char string[100];
gets(string);
int curWordStart = -1;
int curWordEnd = -1;
int wordCount = 0;
int i = 0;
for (i = 0; string[i] != '\0'; i++)
{
if (string[i] == ' ')
{
int curWordLength = curWordEnd - curWordStart + 1;
if (curWordStart != -1 && curWordLength > 0)
{
wordCount++;
int foundMatch = 1;
int j;
int k = 0;
for (j = curWordStart; j <= curWordEnd; j++) {
if (word[k] == '\0') {
foundMatch = 0;
break;
}
if (word[k] != string[j])
{
foundMatch = 0;
break;
}
k++;
}
if (word[k] != '\0')
{
foundMatch = 0;
}
if (foundMatch == 1)
{
printf("%d\n", wordCount);
}
}
curWordStart = -1;
curWordEnd = -1;
}
else if ((string[i] >= 'a' && string[i] <= 'z') || (string[i] >= 'A' && string[i] <= 'Z'))
{
if (curWordStart == -1) {
curWordStart = i;
}
curWordEnd = i;
}
}
int curWordLength = curWordEnd - curWordStart + 1;
if (curWordStart != -1 && curWordLength > 0)
{
wordCount++;
int foundMatch = 1;
int j;
int k = 0;
for (j = curWordStart; j <= curWordEnd; j++) {
if (word[k] == '\0') {
foundMatch = 0;
break;
}
if (word[k] != string[j])
{
foundMatch = 0;
break;
}
k++;
}
if (word[k] != '\0')
{
foundMatch = 0;
}
if (foundMatch == 1)
{
printf("%d\n", wordCount);
}
}
return 0;
}
It will print each position of the searched word in the sentence. If you want to just print the first one, you can easily modify it.
Here are steps to follow:
you must specify precisely what is a word in the string.
measure the length len of the word to search
define an int index = 1
in a loop, using a pointer p starting at the beginning of the string:
advance p past all word delimiters (spaces, punctuation or non letters?)
if p is at end of string return 0 (not found).
measure the length len1 of the current word in the string
if len1 == len and all bytes are identical to those of the word, return index
otherwise skip the word by advancing p by len1, increment index and continue the loop.
Here is an implementation:
#include <stddef.h>
int isletter(char c) {
/* assuming ASCII */
return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
}
int word_index(const char *str, const char *word) {
const char *p = str;
size_t len, len1, i;
int index = 1;
for (len = 0; word[len]; len++)
continue;
for (;;) {
while (!is_letter(*p))
p++;
if (*p == '\0')
return 0;
for (len1 = 0; is_letter(p[len1]); len1++)
continue;
if (len1 == len) {
for (i = 0; i < len && p[i] == word[i]; i++)
continue;
if (i == len)
return index;
}
p += len1;
index++;
}
}

Movement for game character doesn't work at all

Here is the .c code from start to finish. I suspect it's an order of operations issue or something else.
The code is supposed to have a title screen where you can exit or play. If you hit play it renders a new char array in which you can move either left, right, or down (a/d/s). You get points for going down a row each time as well as going over 'P' spots on the array.
Once you hit y-coordinate 202 on the array as well as have positive points, you win and it renders a congrats char array. If you go negative in points (by hitting the '#' paces or the 'L' wall that goes down a row every 1/2 second) then you will lose and be told you lost in a new char array as well as be asked if you want to exit or play again.
And as mentioned before, the movement for the 'L's and the play character 'O' simply doesn't move.
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <fcntl.h>
#include <unistd.h>
char quickchar(float delay);
void render();
void titleRender();
void renderLoss();
void renderWin();
int score();
char titlescreen[20][59] = { };
char diffdiff[20][46] = {
(Grid removed due to char limit)
};
char gameover[20][50] = {
(Grid removed due to char limit)
};
char gameboard[203][26] = {
(Grid removed due to char limit)
};
int playerx;
int playery;
int pts;
void entryRender();
void gameRender();
int main() {
int input;
char replay;
int lx;
int ly;
char walkin;
int gaming;
char titlechoice;
int diff;
int running;
lx = 0;
ly = 0;
running = 1;
playerx = 13;
playery = 5;
pts = 25;
gaming = 0;
while (gaming == 0) {
titleRender();
printf("\033[1;32m");
printf("\nPress 'p' to play or 'x' to exit!");
printf("\033[0m");
scanf(" %c", &titlechoice);
if (titlechoice == 'p') {
gaming += 4;
}
if (titlechoice == 'x') {
return 0;
}
}
while (gaming == 4) {
system("stty -echo raw");
render();
printf("\033[1;35m");
printf("Choose a direction: s/Down, a/Left, d/Right.\n\r");
printf("\033[0m");
walkin = quickchar(0.5);
scanf("%c", &walkin);
//obj behaviour
if (walkin == 's' &&
gameboard[playery +1][playerx] != '#' &&
gameboard[playery + 1][playerx] != '+' &&
gameboard[playery + 1][playerx] != '|' &&
gameboard[playery + 1][playerx] != '-') {
playery++;
pts += 5;
if (gameboard[playery + 1][playerx] == '#') {
pts -= 25;
}
if (gameboard[playery + 1][playerx] == 'P') {
printf("Points increased!\n\r");
pts += 50;
gameboard[playery + 1][playerx] = '_';
}
}
else if (walkin == 'a' &&
gameboard[playery][playerx - 1] != '#' &&
gameboard[playery][playerx - 1] != '+' &&
gameboard[playery][playerx - 1] != '|' &&
gameboard[playery][playerx - 1] != '-') {
playerx--;
if (gameboard[playery][playerx - 1] == '#') {
pts -= 25;
}
if (gameboard[playery][playerx - 1] == 'P') {
printf("Points increased!\n\r");
pts += 50;
gameboard[playery][playerx - 1] = '_';
}
}
else if (walkin == 'd' &&
gameboard[playery][playerx + 1] != '#' &&
gameboard[playery][playerx + 1] != '+' &&
gameboard[playery][playerx + 1] != '|' &&
gameboard[playery][playerx + 1] != '-') {
playerx++;
if (gameboard[playery][playerx + 1] == '#') {
pts -= 25;
}
if (gameboard[playery + 1][playerx] == 'P) {
printf("Points increased!\n\r");
pts += 50;
gameboard[playery][playerx + 1] = '_';
}
}
if (walkin == 'a' || walkin == 's' || walkin == 'd' ||
walkin != 'a' || walkin != ' ' || walkin != 'd' ) {
for (ly = 0; ly = 202; ly++) {
for (lx = 1; lx = 25; lx++) {
gameboard[ly][lx] = 'L';
}
}
}
if (pts <= 0) {
system("clear");
renderLoss();
scanf("%c", replay);
if (replay == 'Y') {
gaming = 3;
}
if (replay == 'N') {
gaming = 5;
}
}
if (playery == 202) {
renderWin();
printf("");
printf("Congrats! You got a score of %d !", pts);
printf("");
scanf("%c", &replay);
if (replay == 'Y') {
gaming = 4;
}
if (replay == 'N') {
gaming = 5;
}
}
//player postion == 203y, then congrta screen
//ask player to set gaming to 4(replay) or none (exit program)
}
system("stty echo -raw");
return 0;
}
void render() {
int y,x,k;
system("clear");
printf("\033[01;33m");
printf("||POINTS: %d||\r\n", pts);
printf("\033[0m");
for (y = 0; y < 203; y++) {
for (x = 0; x < 26; x++) {
if (y == playery && x == playerx) {
printf("\033[0;32m");
printf("O");
printf("\033[0m");
}
else {
printf("\033[1;36m");
printf("%c", gameboard[y][x]);
printf("\033[0m");
}
}
printf("\r\n");
}
}
void titleRender() {
int y, x;
system("clear");
for (y = 0; y < 20; y++) {
for (x = 0; x < 59; x++) {
printf("\033[0;32m");
printf(" %c", titlescreen[y][x]);
printf("\033[0m");
}
printf("\r\n");
}
}
void renderLoss() {
int y, x;
system("clear");
for (y = 0; y < 26; y++) {
for (x = 0; x < 50; x++) {
printf("\033[0;31m");
printf(" %c", gameover[y][x]);
printf("\033[0m");
}
printf("\r\n");
}
}
void renderWin() {
int y, x;
system("clear");
for (y = 0; y < 20; y++) {
for (x = 0; x < 46; x++) {
printf("\033[0;33m");
printf(" %c", diffdiff);
printf("\033[0m");
}
printf("\r\n");
}
}
char quickchar(float delay) {
int flags;
char c;
usleep((int)(delay*1000000));
flags = fcntl(0, F_GETFL, 0);
fcntl(0, F_SETFL, flags | O_NONBLOCK);
c = getchar();
fcntl(0, F_SETFL, flags ^ O_NONBLOCK);
return c;
}

Counting the occurrence of words in a file

My wordOccurrences don't work if you read a file. They can appear twice in the counting so it doesn't count correctly but if I input from stdin it counts correctly.
So I have to read in a file (-i input.txt) count the words and word occurrences in that file. Output the results in the specific file that is given with -o output.txt. If there is a -c it should ignore punctuation and convert to lowercase
MAIN
#include "count.h"
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
//#include "wordOccurances.h"
#include "wordOccurrences.c"
int main(int argc, char **argv)
{
//Initialize variables
FILE *fi; // input file
FILE *fo =stdout; //output file
char buffer[1000];
char *input; //for manually entering string with -c
input = (char*)malloc(100 * sizeof(char));
char *name = "invalid";
int wordcount; // the number of words
char *ch; //a single character
ch = (char*)malloc(100000 * sizeof(char));
int c = 0, i, iFlag = 0, oFlag = 0, cFlag = 0;
char ptr1[50][100];
char *ptr;
if(argc == 1)
{
printf("Default settings\n");
}
else
{
for(i=1; i<argc;i++)
{
if(strcmp(argv[i], "-i")==0)
{
printf("input\n");
iFlag = 1;
fi = fopen(argv[++i],"r");
}
if(strcmp(argv[i], "-o")==0)
{
printf("output\n");
oFlag = 1;
fo = fopen(argv[++i],"w");
}
if(strcmp(argv[i], "-c")==0)
{
cFlag = 1;
}
}
}
if(iFlag ==1)
{
wordcount = countForFile(fi, wordcount);
fprintf(fo,"Word count is: %d \n", wordcount);
wordOccurencesForFile(fi, cFlag,fo);
}
else
{
printf("Enter text: ");
scanf(" %[^\n]s", input);
//Loop through input
int i = 0;
if(cFlag == 1)
{
int i =0;
for( i = 0;input[i]!='\0'; i++)
{
//find upperCase letters
if(input[i] >= 'A' && input[i] <= 'Z')
{
//overwrite to lowerCase
input[i] = tolower(input[i]);
//input[i] = input[i] +32;
}//end of if statement
//ignoring punctuation
if(input[i] == ',' || input[i] == '.' || input[i] == '!' || input[i] == '?' || input[i] == '"' || input[i] == ':' || input[i] ==';' || input[i] == '-')
{
input[i] = ' ';
}
} //end of for loop
}
wordcount = 0;
for(i = 0;input[i] != '\0'; i++)
{
if(input[i] == ' ' && input[i+1] != ' ')
wordcount++;
}// end of while loop
fprintf(fo,"WordCount is: %d\n", wordcount +1);
//count occurrences
wordOccurences(input, fo);
}
if(oFlag == 1)
{fclose(fo);}
}
wordOccurrences
/*
* C Program to Find the Frequency of Every Word in a
* given String
*/
#include <stdio.h>
#include <string.h>
#include "functions.h"
wordOccurences(char *input, FILE *output)
{
int count = 0, c = 0, i, j = 0, k, space = 0;
char str[100], p[50][100], str1[20], ptr1[50][100];
char *ptr;
// printf("Enter the string\n");
//scanf(" %[^\n]s", input);
printf("string length is %d\n", strlen(input));
for (i = 0;i<strlen(input);i++)
{
if ((input[i] == ' ')||(input[i] == ', ')||(input[i] == '.'))
{
space++;
}
}
for (i = 0, j = 0, k = 0;j < strlen(input);j++)
{
if ((input[j] == ' ')||(input[j] == 44)||(input[j] == 46))
{
p[i][k] = '\0';
i++;
k = 0;
}
else
p[i][k++] = input[j];
}
k = 0;
for (i = 0;i <= space;i++)
{
for (j = 0;j <= space;j++)
{
if (i == j)
{
strcpy(ptr1[k], p[i]);
k++;
count++;
break;
}
else
{
if (strcmp(ptr1[j], p[i]) != 0)
continue;
else
break;
}
}
}
for (i = 0;i < count;i++)
{
for (j = 0;j <= space;j++)
{
if (strcmp(ptr1[i], p[j]) == 0)
c++;
}
fprintf(output,"%s -> %d times\n", ptr1[i], c);
c = 0;
}
}
wordOccurencesForFile(FILE *fp, int cFlag, FILE *output)
{
fseek(fp, 0, SEEK_END);
long fsize = ftell(fp);
fseek(fp, 0, SEEK_SET);
char *str = (char*)malloc(fsize + 1);
fread(str, fsize, 1, fp);
fclose(fp);
str[fsize] = 0;
int count = 0, c = 0, i, j = 0, k, space = 0;
char p[1000][512], str1[512], ptr1[1000][512];
char *ptr;
if ( fp )
{
for (i = 0;i<strlen(str);i++)
{
if (cFlag == 1)
{
//ignoring punctuation
if(str[i] == ',' || str[i] == '.' || str[i] == '!'
|| str[i] == '?' || str[i] == '"' || str[i] == ':'
|| str[i] ==';' || str[i] == '-')
{
str[i] = ' ';
}
}
if ((str[i] == ' ')||(str[i] == ',')||(str[i] == '.'))
{
space++;
}
}
for (i = 0, j = 0, k = 0;j < strlen(str);j++)
{
if ((str[j] == ' ')||(str[j] == 44)||(str[j] == 46))
{
p[i][k] = '\0';
i++;
k = 0;
}
else
{
if (cFlag == 1)
{
//find upperCase letters
if(str[j] >= 'A' && str[j] <= 'Z')
{
//overwrite to lowerCase
str[j] = tolower(str[j]);
}//end of if statement
}
p[i][k++] = str[j];
}
}
k = 0;
for (i = 0;i <= space;i++)
{
for (j = 0;j <= space;j++)
{
if (i == j)
{
strcpy(ptr1[k], p[i]);
k++;
count++;
break;
}
else
{
if (strcmp(ptr1[j], p[i]) != 0)
continue;
else
break;
}
}
}
for (i = 0;i < count;i++)
{
for (j = 0;j <= space;j++)
{
if (strcmp(ptr1[i], p[j]) == 0)
c++;
}
fprintf(output,"%s %d \n", ptr1[i], c);
c = 0;
}
}
else
{
printf("Failed to open the file\n");
}
}

Printing string pointers in c

So, essentially I have two files:
File 1:
//
// main.c
// frederickterry
//
// Created by Rick Terry on 1/15/15.
// Copyright (c) 2015 Rick Terry. All rights reserved.
//
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int size (char *g) {
int ofs = 0;
while (*(g+ofs) != '\0') {
++ofs;
}
return ofs;
}
int parse(char *g) {
// Setup
char binaryConnective;
int negated = 0;
// Looking for propositions
int fmlaLength = size(g);
if(fmlaLength == 0) {
return 1;
}
if(fmlaLength == 1) {
if(g[0] == 'p') {
return 1;
} else if (g[0] == 'q') {
return 1;
} else if (g[0] == 'r') {
return 1;
} else {
return 0;
}
}
// Now looking for negated preposition
if(fmlaLength == 2) {
char temp[100];
strcpy(temp, g);
if(g[0] == '-') {
negated = 1;
int negatedprop = parse(g+1);
if(negatedprop == 1) {
return 2;
}
}
}
// Checking if Binary Formula
char arrayleft[50];
char arrayright[50];
char *left = "";
char *right = "";
int numLeft = 0;
int numRight = 0;
int bclocation = 0;
int binarypresent = 0;
if(fmlaLength != 1 && fmlaLength != 2) {
if(g[0] == '-') {
int negatedBinary = parse(g+1);
if(negatedBinary == 1 || negatedBinary == 2 || negatedBinary == 3) {
return 2;
} else {
return 0;
}
}
int i = 0;
int l = 0;
int p = strlen(g);
for(l = 0; l < strlen(g)/2; l++) {
if(g[l] == '(' && g[p-l-1] == ')') {
i++;
}
}
for(int q = i; q < strlen(g); q++) {
if(g[q] == '(') {
numLeft++;
} else if(g[q] == ')') {
numRight++;
}
arrayleft[q] = g[q];
//printf("%c", arrayleft[i]);
//printf("%s", left);
if((numRight == numLeft) && (g[q+1] == 'v' || g[q+1] == '>' || g[q+1] == '^')) {
arrayleft[q+1] = '\0';
bclocation = q+1;
binaryConnective = g[q+1];
binarypresent = 1;
// printf("The binary connecive is: %c\n", binaryConnective);
break;
}
}
if(binarypresent == 0) {
return 0;
}
int j = 0;
for(int i = bclocation+1; i < strlen(g)-1; i++) {
arrayright[j] = g[i];
j++;
}
arrayright[j] = '\0';
left = &arrayleft[1];
right = &arrayright[0];
//printf("Printed a second time, fmla 1 is: %s", left);
int parseleft = parse(left);
// printf("Parse left result: %d\n", parseleft);
if(parseleft == 0) {
return 0;
}
int parseright = parse(right);
if(parseright == 0) {
return 0;
}
// printf("Parse right result: %d\n", parseleft);
if(negated == 1) {
return 2;
} else {
return 3;
}
}
return 0;
}
int type(char *g) {
if(parse(g) == 1 ||parse(g) == 2 || parse(g) == 3) {
if(parse(g) == 1) {
return 1;
}
/* Literals, Positive and Negative */
if(parse(g) == 2 && size(g) == 2) {
return 1;
}
/* Double Negations */
if(g[0] == '-' && g[1] == '-') {
return 4;
}
/* Alpha & Beta Formulas */
char binaryConnective;
int numLeft = 0;
int numRight = 0;
int bclocation = 0;
int binarypresent = 0;
int i = 0;
if(g[0] == '(') {
i++;
}
if(g[0] == '-') {
i++;
if(g[1] == '(') {
i++;
}
}
for(i; i < strlen(g); ++i) {
if(g[i] == '(') {
numLeft++;
} else if(g[i] == ')') {
numRight++;
}
if(numRight == numLeft) {
if(g[i+1] == 'v' || g[i+1] == '>' || g[i+1] == '^') {
bclocation = i+1;
binaryConnective = g[i+1];
binarypresent = 1;
break;
}
}
}
/* Connective established */
if(binaryConnective == '^') {
if(g[0] == '-') {
return 3;
} else {
return 2;
}
} else if(binaryConnective == '>') {
if(g[0] == '-') {
return 2;
} else {
return 3;
}
} else if (binaryConnective == 'v') {
if(g[0] == '-') {
return 2;
} else {
return 3;
}
}
}
return 0;
}
char bin(char *g) {
char binaryConnective;
char arrayLeft[50];
int numLeft = 0;
int numRight = 0;
int bclocation = 0;
int i = 0;
if(g[0] == '(') {
i++;
}
if(g[0] == '-') {
i++;
if(g[1] == '(') {
i++;
}
}
for(i; i < strlen(g); ++i) {
if(g[i] == '(') {
numLeft++;
} else if(g[i] == ')') {
numRight++;
}
int j = 0;
arrayLeft[j++] = g[i];
if(numRight == numLeft) {
if(g[i+1] == 'v' || g[i+1] == '>' || g[i+1] == '^') {
arrayLeft[i+1] = '\0';
bclocation = i+1;
binaryConnective = g[i+1];
return binaryConnective;
}
}
}
return binaryConnective;
}
char *partone(char *g) {
char binaryConnective;
char arrayLeft[50];
char arrayRight[50];
int numLeft = 0;
int numRight = 0;
int bclocation = 0;
int i = 0;
if(g[0] == '(') {
i++;
}
if(g[0] == '-') {
i++;
if(g[1] == '(') {
i++;
}
}
int j = 0;
for(i; i < strlen(g); ++i) {
if(g[i] == '(') {
numLeft++;
} else if(g[i] == ')') {
numRight++;
}
arrayLeft[j] = g[i];
if(numRight == numLeft) {
if(g[i+1] == 'v' || g[i+1] == '>' || g[i+1] == '^') {
arrayLeft[j+1] = '\0';
bclocation = i+1;
binaryConnective = g[i+1];
break;
}
}
j++;
}
int m = 0;
for(int k = bclocation+1; k < strlen(g)-1; k++) {
arrayRight[m] = g[k];
m++;
}
arrayRight[m] = '\0';
char* leftSide = &arrayLeft[0];
// printf("%s\n", leftSide);
// printf("%s\n", rightSide);
int k = 0;
k++;
return leftSide;
}
char *parttwo(char *g) {
char binaryConnective;
char arrayLeft[50];
char arrayRight[50];
int numLeft = 0;
int numRight = 0;
int bclocation = 0;
int i = 0;
if(g[0] == '(') {
i++;
}
if(g[0] == '-') {
i++;
if(g[1] == '(') {
i++;
}
}
int j = 0;
for(i; i < strlen(g); ++i) {
if(g[i] == '(') {
numLeft++;
} else if(g[i] == ')') {
numRight++;
}
arrayLeft[j] = g[i];
if(numRight == numLeft) {
if(g[i+1] == 'v' || g[i+1] == '>' || g[i+1] == '^') {
arrayLeft[j+1] = '\0';
bclocation = i+1;
binaryConnective = g[i+1];
break;
}
}
j++;
}
int m = 0;
int n = size(g) - 1;
if(g[strlen(g)-1] != ')') {
n++;
}
for(int k = bclocation+1; k < n; k++) {
arrayRight[m] = g[k];
m++;
}
arrayRight[m] = '\0';
char* leftSide = &arrayLeft[0];
char* rightSide = &arrayRight[0];
// printf("%s\n", leftSide);
// printf("%s\n", rightSide);
return rightSide;
}
char *firstexp(char *g) {
char* left = partone(g);
char leftArray[50];
int i = 0;
for(i; i < strlen(left); i++) {
leftArray[i] = left[i];
}
leftArray[i] = '\0';
char binConnective = bin(g);
int typeG = type(g);
if(typeG == 2) {
if(binConnective == '^') {
return &leftArray;
} else if(binConnective == '>') {
return &leftArray;
}
} else if(typeG == 3) {
if(binConnective == 'v')
return &leftArray;
}
char temp[50];
for(int i = 0; i < strlen(leftArray); i++) {
temp[i+1] = leftArray[i];
}
temp[0] = '-';
char* lefttwo = &temp[0];
if(typeG == 2) {
if(binConnective == 'v') {
return lefttwo;
}
} else if(typeG == 3) {
if(binConnective == '>' || binConnective == '^') {
return lefttwo;
}
}
return "Hello";
}
char *secondexp(char *g) {
// char binaryConnective = bin(g);
// char* right = parttwo(g);
// char rightArray[50];
// int i = 0;
// for(i; i< strlen(right); i++) {
// rightArray[i+1] = right[i];
// }
// rightArray[i] = '\0';
// int typeG = type(g);
// if(type(g) == 2) {
// if(binaryConnective == '^') {
// return &rightArray;
// }
// } else if(type(g) == 3) {
// if(binaryConnective == 'v' || binaryConnective == '>') {
// return &rightArray;
// }
// }
return "Hello";
}
typedef struct tableau tableau;
\
\
struct tableau {
char *root;
tableau *left;
tableau *right;
tableau *parent;
int closedbranch;
};
int closed(tableau *t) {
return 0;
}
void complete(tableau *t) {
}
/*int main(int argc, const char * argv[])
{
printf("Hello, World!\n");
printf("%d \n", parse("p^q"));
printf("%d \n", type("p^q"));
printf("%c \n", bin("p^q"));
printf("%s\n", partone("p^q"));
printf("%s\n", parttwo("p^q"));
printf("%s\n", firstexp("p^q"));
printf("Simulation complete");
return 0;
}*/
File 2:
#include <stdio.h>
#include <string.h> /* for all the new-fangled string functions */
#include <stdlib.h> /* malloc, free, rand */
#include "yourfile.h"
int Fsize = 50;
int main()
{ /*input a string and check if its a propositional formula */
char *name = malloc(Fsize);
printf("Enter a formula:");
scanf("%s", name);
int p=parse(name);
switch(p)
{case(0): printf("not a formula");break;
case(1): printf("a proposition");break;
case(2): printf("a negated formula");break;
case(3): printf("a binary formula");break;
default: printf("what the f***!");
}
printf("\n");
if (p==3)
{
printf("the first part is %s and the second part is %s", partone(name), parttwo(name));
printf(" the binary connective is %c \n", bin(name));
}
int t =type(name);
switch(t)
{case(0):printf("I told you, not a formula");break;
case(1): printf("A literal");break;
case(2): printf("An alpha formula, ");break;
case(3): printf("A beta formula, ");break;
case(4): printf("Double negation");break;
default: printf("SOmewthing's wrong");
}
if(t==2) printf("first expansion fmla is %s, second expansion fmla is %s\n", firstexp(name), secondexp(name));
if(t==3) printf("first expansion fmla is %s, second expansion fmla is %s\n", firstexp(name), secondexp(name));
tableau tab;
tab.root = name;
tab.left=0;
tab.parent=0;
tab.right=0;
tab.closedbranch=0;
complete(&tab);/*expand the root node then recursively expand any child nodes */
if (closed(&tab)) printf("%s is not satisfiable", name);
else printf("%s is satisfiable", name);
return(0);
}
If you look at the first file, you'll see a method called * firstexp(char * g).
This method runs perfectly, but only if another method called * secondexp(char * g) is commented out.
If * secondexp(char * g) is commented out, then *firstexp runs like this:
Enter a formula:((pvq)>-p)
a binary formula
the first part is (pvq) and the second part is -p the binary connective is >
A beta formula, first expansion fmla is -(pvq), second expansion fmla is Hello
((pvq)>-p) is satisfiableProgram ended with exit code: 0
otherwise, if *secondexp is not commented out, it runs like this:
Enter a formula:((pvq)>-p)
a binary formula
the first part is (pvq) and the second part is -p the binary connective is >
A beta formula, first expansion fmla is \240L, second expansion fmla is (-
((pvq)>-p) is satisfiable. Program ended with exit code: 0
As you can see, the outputs are completely different despite the same input. Can someone explain what's going on here?
In the commented-out parts of secondexp and in parttwo, you return the address of a local variable, which you shouldn't do.
You seem to fill a lot of ad-hoc sized auxiliary arrays. These have the problem that they might overflow for larger expressions and also that you cannot return them unless you allocate them on the heap with malloc, which also means that you have to free them later.
At first glance, the strings you want to return are substrings or slices of the expression string. That means that the data for these strings is already there.
You could (safely) return pointers into that string. That is what, for example strchr and strstr do. If you are willing to modify the original string, you could also place null terminators '\0' after substrings. That's what strtok does, and it has the disadvantage that you lose the information at that place: If you string is a*b and you modify it to a\0b, you will not know which operator there was.
Another method is to create a struct that stores a slice as pointer into the string and a length:
struct slice {
const char *p;
int length;
};
You can then safely return slices of the original string without needing to worry about additional memory.
You can also use the standard functions in most cases, if you stick to the strn variants. When you print a slice, you can do so by specifying a field width in printf formats:
printf("Second part: '%.*s'\n", s->length, s->p);
In your parttwo() function you return the address of a local variable
return rightSide;
where rightSide is a pointer to a local variable.
It appears that your compiler gave you a warning about this which you solved by making a pointer to the local variabe arrayRight, that may confuse the compiler but the result will be the same, the data in arrayRight will no longer exist after the function returns.
You are doing the same all over your code, and even worse, in the secondexp() function you return a the address of a local variable taking it's address, you are not only returning the address to a local variabel, but also with a type that is not compatible with the return type of the function.
This is one of many probable issues that your code may have, but you need to start fixing that to continue with other possible problems.
Note: enable extra warnings when compiler and listen to them, don't try to fool the compiler unless you know exactly what you're doing.

C Recursive WordSearch solver in all directions

In the main file, I loop through each line of input until it hits the words, then I pass the word its searching for to startSearch with puzzleArray, the solvedArray I want to get back, the word as string, size as number of rows, and length as number of columns.
Currently, I keep getting segmentation faults/or endless loops. Any help over my algorithm/code would be greatly appreciated.
void startSearch(char** puzzleArray,char** solvedArray,char* string,int size,int length)
{
char* direction = "";
int solved = 1;
int j = 0;
while( j <= 7 && solved != 0)
{
if(j == 0)
{
direction = "up";
}
else if(j == 1)
{
direction = "upRight";
}
else if(j == 2)
{
direction = "right";
}
else if(j == 3)
{
direction = "downRight";
}
else if(j == 4)
{
direction = "down";
}
else if(j == 5)
{
direction = "downLeft";
}
else if(j == 6)
{
direction = "left";
}
else if(j == 7)
{
direction = "upLeft";
}
solved = recursiveSearch(puzzleArray,solvedArray,string,direction,size,length,0,0,0);
j++;
}
}
int recursiveSearch(char** puzzleArray,char** solvedArray,char* string,char* direction,int sizeOfPuzzle,int lengthOfArrayWithSpaces,int rowPos,int colPos,int stringPosition)
{
int lengthOfWord;
int i = rowPos;
int j = colPos;
int found = 0;
int empty = 1;
char c = string[stringPosition];
int position = stringPosition;
lengthOfWord = lengthOfArray(string);
if(string[position+1] == '\0')
{
return 0;
}
while(empty != 0)
{
if(string[stringPosition] == puzzleArray[i][j])
{
found = 1;
}
else if(rowPos < sizeOfPuzzle && colPos < lengthOfArrayWithSpaces)
{
stringPosition = 0;
for(i = rowPos; i < sizeOfPuzzle && found != 1; i++)
{
for(j = colPos; j < puzzleArray[rowPos][colPos] != '\0' && found != 1; j++)
{
if(string[stringPosition] == puzzleArray[i][j])
{
found = 1;
rowPos = i;
colPos = j;
stringPosition = 0;
}
}
}
if(found == 0)
{
empty = 1;
}
}
if(found == 1)
{
position = stringPosition + 1;
if(rowPos-1 >= 0)
{
//printf("\nString:%cPuzzleArray:%c",string[position],puzzleArray[rowPos-1][colPos]);
if(string[position] == puzzleArray[rowPos-1][colPos] && direction == "up")
{
//printf("UP");
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos-1,colPos,position+1))
{
solvedArray[rowPos-1][colPos] = puzzleArray[rowPos-1][colPos];
return 0;
}
}
else if(colPos+2 <= lengthOfArrayWithSpaces)
{
if(string[position] == puzzleArray[rowPos-1][colPos+2] && direction == "upRight")
{
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos-1,colPos+2,position+1))
{
solvedArray[rowPos-1][colPos+2] = puzzleArray[rowPos-1][colPos+2];
return 0;
}
}
}
}
if(colPos+2 <= lengthOfArrayWithSpaces)
{
if(string[position] == puzzleArray[rowPos][colPos+2] && direction == "right")
{
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos,colPos+2,position+1))
{
solvedArray[rowPos][colPos+2] = puzzleArray[rowPos][colPos+2];
return 0;
}
}
if(rowPos+1 <= lengthOfArrayWithSpaces)
{
if(string[position] == puzzleArray[rowPos+1][colPos+2] && direction == "downRight")
{
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos+1,colPos+2,position+1))
{
solvedArray[rowPos+1][colPos+2] = puzzleArray[rowPos+1][colPos+2];
return 0;
}
}
}
}
if(rowPos+1 <= sizeOfPuzzle)
{
if(string[position] == puzzleArray[rowPos+1][colPos] && direction == "down")
{
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos+1,colPos,position+1))
{
solvedArray[rowPos+1][colPos] = puzzleArray[rowPos+1][colPos];
return 0;
}
}
if(rowPos + 1 <= lengthOfArrayWithSpaces)
{
if(string[position] == puzzleArray[rowPos+1][colPos-2] && direction == "downLeft")
{
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos+1,colPos-2,position+1))
{
solvedArray[rowPos+1][colPos-2] = puzzleArray[rowPos+1][colPos-2];
return 0;
}
}
}
}
if(colPos-2 >= 0)
{
if(string[position] == puzzleArray[rowPos][colPos-2] && direction == "left")
{
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos+1,colPos+2,position+1))
{
solvedArray[rowPos+1][colPos+2] = puzzleArray[rowPos+1][colPos+2];
return 0;
}
}
if(rowPos - 1 >= 0)
{
if(string[position] == puzzleArray[rowPos-1][colPos-2] && direction == "upLeft")
{
if(recursiveSearch(puzzleArray,solvedArray,string,direction,sizeOfPuzzle,lengthOfArrayWithSpaces,rowPos-1,colPos-2,position+1))
{
solvedArray[rowPos-1][colPos-2] = puzzleArray[rowPos-1][colPos-2];
return 0;
}
}
}
}
}
}
return 1;
}
direction == "up"
This is not how you compare two strings to be equal. Use strcmp / strncmp for string comparison. This kind of comparison appears all over your code.
Also:
for(j = colPos; j < puzzleArray[rowPos][colPos] != '\0' && found != 1; j++)
This j < puzzleArray[rowPos][colPos] != '\0' looks dubious, what are you trying to do?

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