I am writing a program that translates letters into morse code and then transmits them to an LED and blinks. I am not able to return the value ".- -..."
#include <stdio.h>
#include <string.h>
char *encode()
{
char *name = "AB";
char name_m[100] = "";
for (int i = 0; i < strlen(name); i++)
{
if (name[i] == 65)
{
strcat(name_m, ".- ");
}
else if (name[i] == 66)
{
strcat(name_m, "-...");
}
};
printf("%s", name_m);
return name_m;
}
int main()
{
char *name_m;
name_m = encode();
printf("\n%s", name_m);
}
main.c:22:10: warning: function returns address of local variable [-Wreturn-local-addr]
22 | return name_m;
| ^~~~~~
.- -...
(null)
In C you cant return reference (pointer) to local variable as it stops to exist when function returns.
You need to pass te buffer to the function:
char *encode(char *name_m, const char *name)
{
for (int i = 0; i < strlen(name); i++)
{
if (name[i] == 'A')
{
strcat(name_m, ".- ");
}
else if (name[i] == 'B')
{
strcat(name_m, "-...");
}
}
printf("%s", name_m);
return name_m;
}
allocate it dynamically:
char *encode( const char *name)
{
char *name_m = malloc(100);
if(name_m)
{
for (int i = 0; i < strlen(name); i++)
{
if (name[i] == 'A')
{
strcat(name_m, ".- ");
}
else if (name[i] == 'B')
{
strcat(name_m, "-...");
}
}
printf("%s", name_m);
}
return name_m;
}
or the worst solution - define it as static
char *encode( const char *name)
{
static char name_m[100];
if(name_m)
{
for (int i = 0; i < strlen(name); i++)
{
if (name[i] == 'A')
{
strcat(name_m, ".- ");
}
else if (name[i] == 'B')
{
strcat(name_m, "-...");
}
}
printf("%s", name_m);
}
return name_m;
}
Related
can you help me with the size of the digits, for example, when I enter 01234, then everything works as it should, but it shouldn’t, the limit of digits should be within four.When I enter some four-digit number, everything works as it should work. But when some five-digit, six-digit or even more, then everything works as if it should be, but it should not work like that. And when I enter numbers that are less than four-digit, for example 123 , then it gives an error and it's good. But when I enter numbers that are more than four digits, it does not give an error and works as if it should be so.
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
typedef struct s_mastermind {
int my_attempt;
char* my_code;
} my_mastermind;
my_mastermind* settings_function(my_mastermind* mastermind, int argc, char** argv);
int checking_for_correctness_num(char* _string);
int wrong_input(int progress,char* num_code);
my_mastermind* my_function();
int check_function(char* string);
char* input_function();
int mis_placed_pieces(char* bit, char* num_code);
int well_placed_pieces(char* bit, char* num_code);
int code_checker(char* bit, char* num_code);
char* size_of_function(char* strye);
char* my_strcpy(char* num1, char* num2) {
for(int i = 0; num2[i] != 0; i++) {
num1[i] = num2[i];
}
return num1;
}
int my_strlen(char* num1) {
return (*num1) ? my_strlen(++num1) + 1 : 0;
}
my_mastermind* my_function() {
my_mastermind* num = malloc(sizeof(my_mastermind));
num->my_code = malloc(5);
num->my_code[4] = '\0';
my_strcpy(num->my_code, "");
num->my_attempt = 10;
return num;
}
my_mastermind* settings_function(my_mastermind* mastermind, int argc, char** argv) {
char* bit;
for(int i = 0; i < argc;) {
if (my_strlen(argv[i]) == 2 && argv[i][0] == '-') {
if(argv[i][1] == 'c') {
char* num_code = argv[i + 1];
if(wrong_input(argc,num_code) != 0) {
break;
}
my_strcpy(mastermind->my_code, num_code);
}else if(argv[i][1] == 't') {
if(checking_for_correctness_num(argv[i + 1]) == 0) {
mastermind->my_attempt = check_function(argv[i + 1]);
}
} else {
printf("WRONG FLAG RESTART THE GAME!!!\n");
}
}
i += 1;
}
return mastermind;
}
int wrong_input(int progress,char* num_code) {
// if(my_strlen(num_code) != 4) {
// printf("Code bigger than 4\n");
// }
if(checking_for_correctness_num(num_code) == 1) {
printf("Wrong input!\n> ");
fflush(stdout);
char* code = input_function();
char* variable = size_of_function(code);
free(code);
int results = 1;
if(wrong_input(progress,variable) == 0) {
results = code_checker(num_code, variable);
}
free(variable);
return results;
}
return 0;
}
int checking_for_correctness_num(char* _string) {
for(int i = 0; _string[i] != '\0'; i++) {
if(!(_string[i] >= '0' && _string[i] <= '9')) {
return 1;
}
}
return 0;
}
int check_function(char* string) {
int check_num = 0;
for(int i = 0; string[i] != '\0'; i++) {
check_num = check_num * 10 + (string[i] - '0');
}
return check_num;
}
char* input_function() {
char* getting = malloc(101);
getting[100] = '\0';
read(0, getting, 100);
fflush(stdout);
return getting;
}
int game_progress(int progress, char* bit) {
printf("Round: %d\n> ", progress);
fflush(stdout);
char* code = input_function();
char* variable = size_of_function(code);
free(code);
int results = 1;
if(wrong_input(progress,variable) == 0) {
results = code_checker(bit, variable);
}
free(variable);
return results;
}
void game_action(my_mastermind* mastermind) {
int current_try = 0;
for (;current_try < mastermind->my_attempt;) {
int results = game_progress(current_try, mastermind->my_code);
current_try += 1;
if(results == 0) {
printf("Congratz! You did it!\n");
break;
}
}
}
int code_checker(char* bit, char* num_code) {
int good_w = well_placed_pieces(bit, num_code);
int not_good_m = mis_placed_pieces(bit, num_code);
if(good_w == 3 || good_w == 2 || good_w == 1 || not_good_m == 3 || not_good_m == 2 || not_good_m == 1){
printf("Well placed pieces: %d\nMisplaced pieces: %d\n---\n", good_w,not_good_m);
}
if(good_w == 4) {
return 0;
} else {
return 1;
}
}
int well_placed_pieces(char* bit, char* num_code) {
int number = 0;
for(int i = 0; i < 4; i++) {
if (bit[i] == num_code[i]) {
number += 1;
}
}
return number;
}
int mis_placed_pieces(char* bit, char* num_code) {
int number = 0;
int i = 0;
int j = 0;
while(i < 4) {
i++;
if (bit[i] == num_code[i]) {
number += 1;
}
}
return number;
}
char* size_of_function(char* strye) {
char* new_string = malloc(5);
new_string[4] = '\0';
for(int i = 0; i < 4;i++){
new_string[i] = strye[i];
}
return new_string;
}
int main(int argc, char** argv) {
printf("Will you find the secret code?\n---\n");
my_mastermind* mastermind = my_function();
settings_function(mastermind, argc, argv);
game_action(mastermind);
free(mastermind);
return 0;
}
The problem is that you size_of_function assumes the input string is exactly 4 character long, not counting the '\0'. You should either check if the input string and return a error via a NULL pointer, or fully copy the string and check later.
Returning a NULL pointer require the least modification. You can do it by checking the input string size first :
char* size_of_function(char* strye) {
if(my_strlen(strye) != 4)
return NULL;
char* new_string = malloc(5);
new_string[4] = '\0';
for(int i = 0; i < 4;i++){
new_string[i] = strye[i];
}
if (strye[4] == '\r' || strye[4] == '\n' || strye[4] == '\0')
return new_string;
free(new_string);
return NULL;
}
Then, in wrong_input(), check if num_code is NULL :
int wrong_input(int progress,char* num_code) {
if(num_code == NULL || checking_for_correctness_num(num_code) == 1) {
printf("Wrong input!\n> ");
fflush(stdout);
char* code = input_function();
char* variable = size_of_function(code);
free(code);
int results = 1;
if(wrong_input(progress,variable) == 0) {
results = code_checker(num_code, variable);
}
free(variable);
return results;
}
return 0;
}
It is critical to check if num_code is NULL before calling checking_for_correctness_num(). In C the || operator evaluates the left operand first and skip the second operand evaluation if the first one is true. This way we can ensure that we never pass a NULL pointer to checking_for_correctness_num().
wrong_input() is called recursively and allocates memory without freeing it before calling itself. This can eat up memory fast and is generality considered to be bad practice.
Also, you've implemented my_strlen() as a recursive function, which isn't necessary. Using a loop is better :
int my_strlen(char* num1) {
int index = 0;
while(num1[index++]); //Note that 'index' is post-incremented
return index - 1; //Subtract one to account for the last post increment
}
Why do I get an error when I insert something like ';' or '&' in a Palindrome program?
I'd like to create a Palindrome program that automatically excludes special symbols.
eg:
mad!am -> The Palindrome is correct.
But it doesn't work. It only works when I put madam, but when I put mad!am, it gives an error.
#include <stdio.h>
#include <stdlib.h>
#include<string.h>
#define MAX_STACK_SIZE 100
typedef char element;
typedef struct {
element data[MAX_STACK_SIZE];
int top;
} StackType;
void init_stack(StackType* s)
{
s->top = -1;
}
int is_empty(StackType* s)
{
return (s->top == -1);
}
int is_full(StackType* s)
{
return (s->top == (MAX_STACK_SIZE - 1));
}
void push(StackType* s, element item)
{
if (is_full(s)) {
fprintf(stderr, "error\n");
return;
}
else s->data[++(s->top)] = item;
}
element pop(StackType* s)
{
if (is_empty(s)) {
fprintf(stderr, "error\n");
exit(1);
}
else return s->data[(s->top)--];
}
element peek(StackType* s)
{
if (is_empty(s)) {
fprintf(stderr, "error\n");
exit(1);
}
else return s->data[s->top];
}
int main(void)
{
StackType s, a, k;
init_stack(&s);
init_stack(&a);
init_stack(&k);
int i=0;
char input[MAX_STACK_SIZE];
printf("문자열을 입력하세요: ");
scanf("%s", input);
int length = strlen(input);
for (int i = 0; i < length; i++) {
if ('a' <= input[i] && input[i] <= 'z') {
push(&s, input[i]);
push(&a, input[i]);
}
else if ('A' <= input[i] && input[i] <= 'Z') {
push(&s, input[i] - ('A' - 'a'));
push(&a, input[i] - ('A' - 'a'));
}
}
for (int i = 0; i < length; i++)
{
push(&k, pop(&s));
}
while (k.data[MAX_STACK_SIZE]!=NULL) {
if (peek(&a) != peek(&k))
{
printf("not palindrome \n");
break;
return 0;
}
pop(&k);
pop(&a);
printf("palindrome ok!\n");
}
return 0;
}
Avoid constructs like if ('a' <= input[i] && input[i] <= 'z'). That's just makes a mess. In your case, just use isalpha().
But the problem lies in the for loop after you have read all the characters. Since you're skipping characters you cannot use length again. Do these changes:
int length = strlen(input);
int no_letters=0;
for (int i = 0; i < length; i++) {
if (isalpha(input[i])) {
push(&s, input[i]);
push(&a, input[i]);
no_letters++;
}
}
for (int i = 0; i < no_letters; i++)
{
push(&k, pop(&s));
}
There was a small bug with length.. You should ignore counting string length for those element which should not be counted.. Here I have corrected the code with comment , compiled and run.. It is working correct now...
Please try below code... I have added comment what I added..
#include <stdio.h>
#include <stdlib.h>
#include<string.h>
#define MAX_STACK_SIZE 100
typedef char element;
typedef struct {
element data[MAX_STACK_SIZE];
int top;
} StackType;
void init_stack(StackType* s)
{
s->top = -1;
}
int is_empty(StackType* s)
{
return (s->top == -1);
}
int is_full(StackType* s)
{
return (s->top == (MAX_STACK_SIZE - 1));
}
void push(StackType* s, element item)
{
if (is_full(s)) {
fprintf(stderr, "error\n");
return;
}
else s->data[++(s->top)] = item;
}
element pop(StackType* s)
{
if (is_empty(s)) {
fprintf(stderr, "error\n");
exit(1);
}
else return s->data[(s->top)--];
}
element peek(StackType* s)
{
if (is_empty(s)) {
fprintf(stderr, "error\n");
exit(1);
}
else return s->data[s->top];
}
int main(void)
{
StackType s, a, k;
init_stack(&s);
init_stack(&a);
init_stack(&k);
int i=0;
char input[MAX_STACK_SIZE];
printf("문자열을 입력하세요: ");
scanf("%s", input);
int length = strlen(input);
int len=0; // added
for (int i = 0; i < length; i++) {
if ('a' <= input[i] && input[i] <= 'z') {
push(&s, input[i]);
push(&a, input[i]);
len++; //counting length for valid characters
}
else if ('A' <= input[i] && input[i] <= 'Z') {
push(&s, input[i] - ('A' - 'a'));
push(&a, input[i] - ('A' - 'a'));
len++; //counting length for valid characters only
}
}
for (int i = 0; i < len; i++)
{
push(&k, pop(&s));
}
while (k.data[MAX_STACK_SIZE]!=NULL) {
if (peek(&a) != peek(&k))
{
printf("not palindrome \n");
break;
return 0;
}
pop(&k);
pop(&a);
printf("palindrome ok!\n");
}
return 0;
}
I now need to output the Morse code equivalent of alphanumeric input. My condition for check this is an if loop: I try to look at each element of input array with each element of the alpha array but a match never seems to be found. I am not sure if I am using the correct method. I try to de-reference the point to input and compare the value with each element of alpha until a match is found. If no match is found then an error occurs.
Not working:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <ctype.h>
int main(void)
{
char *morse[] = {"/",
".-","-...","-.-.","-..",".","..-.","--","....","..",".---",
"-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-",
"..-","...-",".--","-..-","-.--","--..",
"-----",".----","..---","...--","....-",".....","-....","--...","---..","----."};
char *alpha[]= {" ",
"A","B","C","D","E","F","G","H","I","J",
"K","L","M","N","O","P","Q","R","S","T",
"U","V","W","X","Y", "Z",
"0", "1","2","3","4","5","6","7","8","9"};
char *print_array[50];
int print_array_index = 0;
char hold[50];
int hold_index = 0;
char input[200];
int i = 0;
printf("welcome to the Morse translator.\n");
printf("Enter input: ");
fgets(input, sizeof(input), stdin);
char *p;
for (p=input; *p !='\0';++p)
{
*p = toupper(*p);
}
if (input[0]=='-' || input[0]=='.')
{
while (input[i] !='\0') {
if (input[i] ==' ' || input[i] == '\n')
{
hold[hold_index] = '\0';
bool found = false;
for (int x = 0; x < sizeof(morse) / sizeof(char *); x++)
{
if (strcmp(morse[x], hold) == 0)
{
print_array[print_array_index++] = alpha[x];
found = true;
break;
}
}
if (!found)
{
fprintf(stderr, "invalid Morse code!\n");
}
hold_index = 0;
}
else
{
hold[hold_index++] = input[i];
}
i++;
}
for (int x = 0; x < print_array_index; x++)
{
printf("%s", print_array[x]);
}
printf("\n");
}
else if (isalnum(input[0]))
{
while (input[i]!='\0')
{
if (input[i] ==' ' || input[i] == '\n')
{
bool found = false;
for (int x=0; x < sizeof(alpha)/sizeof (char*);x++)
{
if (alpha[x]==input[i])
{
print_array [print_array_index++] = alpha[x];
found = true;
break;
}
}
if (!found)
{
fprintf(stderr, "Invalid input!\n");
}
hold_index = 0;
}
i++;
}
for (int x=0; x < print_array_index; x++)
{
printf("%s",print_array[x]);
}
printf("\n");
}
return 0;
}
part of else if (isalnum(input[0])){ should be something like
else if (isalnum(input[0])){
while (input[i]!='\0' && input[i]!='\n'){
bool found = false;
for (int x=0; x < sizeof(alpha)/sizeof(char*);x++){
if (*alpha[x]==input[i]){
print_array[print_array_index++] = morse[x];
found = true;
break;
}
}
if(!found){
fprintf(stderr, "Invalid input!\n");
}
i++;
}
for (int x=0; x < print_array_index; x++){
printf("%s", print_array[x]);
}
printf("\n");
}
Below is the code template and under /* write your code here */ is my own code.
The template should be correct but there is sth wrong with my code.
My algorithm is to iterate through str until finding the null character.
Then compare each character, if they are the same then iterate through both str and sub, otherwise set continue to iterate through str and reset to the first character of substr.
#include <stdio.h>
int findSubstring(char *str, char *substring);
int main()
{
char str[40], substr[40];
printf("Enter the string: ");
gets(str);
printf("Enter the substring: ");
gets(substr);
printf("findSubstring(): %d\n", findSubstring(str, substr));
return 0;
}
int findSubstring(char *str, char *substr)
{
/* write your code here */
int i = 0, j = 0;
while ((str[j] != '\0')||(substr[i] != '\0')) {
if (substr[i] != str[j]) {
j++;
i = 0;
}
else {
i++;
j++;
}
}
if (substr[i] == '\0')
return 1;
else
return -1;
}
Do not use gets(), which has unavoidable risk of buffer overrun.
The condition of the loop is wrong. The loop should exited if one of *(str + j) or *(substr + i) is a (terminating) null character.
Fixed code:
#include <stdio.h>
int findSubstring(char *str, char *substring);
void safer_gets(char *str, size_t max);
int main(void)
{
char str[40], substr[40];
printf("Enter the string: ");
safer_gets(str, sizeof(str));
printf("Enter the substring: ");
safer_gets(substr, sizeof(str));
printf("findSubstring(): %d\n", findSubstring(str, substr));
return 0;
}
int findSubstring(char *str, char *substr)
{
int i = 0, j = 0;
while ((*(str + j) != '\0')&&(*(substr + i) != '\0')) {
if (*(substr + i) != *(str + j)) {
j++;
i = 0;
}
else {
i++;
j++;
}
}
if (*(substr + i) == '\0')
return 1;
else
return -1;
}
void safer_gets(char *str, size_t max)
{
int i;
fgets(str, max, stdin);
for (i = 0; *(str + i) != '\0'; i++) {
if (*(str + i) == '\n') {
*(str + i) = '\0';
break;
}
}
}
/*--------------------------One more simple example-----------------------------
Find the words from a set of words containing a given substring?
Input: Set of Words: [blackcat, blackdog, blackrat, whitetiger, blueelephant],
Substring: black
Output:[blackcat, blackdog, blackrat]
-----------------------------------------------------------------------------------------*/
#include <iostream>
#include <cstring>
int substring(char* sub,char* string);
int main()
{
const char* Names[] { "blackcat", "blackdog", "blackrat", "whitetiger", "blueelephant" };
char substr[]{ "black" };
int found{ -1 };
for (auto strings: Names)
{
found = substring(substr, const_cast<char*>(strings));
if (found != -1) {
std::cout << strings << " ";
}
}
std::cout << std::endl;
return 0;
}
int substring(char* sub, char* string)
{
int i{};
int j{};
while ((string[i] != '\0') && (sub[j] != '\0'))
{
if (string[i] != sub[j]) {
j++;
i = 0;
}
else {
i++;
j++;
}
}
if (sub[j] == '\0' && i != 0) {
return 1;
}
else {
return -1;
}
}
#include<stdio.h>
#include<conio.h>
void main()
{
char s[100],sub[50];
int i,j,c=0;
clrscr();
printf("enter string and substring\n");
gets(s);
printf("\n");
gets(sub);
printf("\n");
i=0;
j=0;
while(s[i]!='\0')
{
if(s[i]!=sub[j])
i++;
else if(s[i]==sub[j])
{
while(sub[j]!='\0')
{
if(s[i]==sub[j])
{
i++;
j++;
c++;
}
else
{
c=0;
break;
}
}
}
}
if(c!=0)
printf("\nsubstring is present \n ");
else
printf("\nsubstring is absent \n ");
getch();
}
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.