So i'm new to c and I have 2 problems with this code:
#import <stdio.h>
int main(){
char answer;
int playerX = 0;
int playerY = 0;
int done = 0;
char direction[] = "none";
while (done == 0){
printf("Direction:\n");
a = getchar();
if (answer == "u"){
playerY += 1;
} else{
}
printf("Your current position is: %d,%d\n", playerX, playerY);
}
return 0;
}
On line 14 it says "warning: comparison between pointer and integer"
With only 1 input (being u) and nothing else I see this:
Direction:
u
Your current position is: 0,0
Direction:
Your current position is: 0,0
Direction:
First of all, I am assuming you have "#include" instead of "import" in line 1, and "answer" instead of "a" in line 12.
To answer the actual question you have, in C char and string are different. You have a char type variable answer, that you are comparing with the string "u". As a result, the compiler is creating a constant string "u" and comparing the pointer to that string with the char type variable answer. Your check should instead have
if(answer == 'u') {
Related
I'm writing a code that must identify the letter 't' or 'T' in a word, before or after the middle of it.
If the first half of the word does contain a 't' or a 'T', the program should output a 1. If the first half does not contain the letter 't' or 'T', but the second half does, then the program should output a 2. Otherwise, if there is no 't' or 'T' in the word at all, the program's output should be -1. The word entered will not have more than 50 letters.
#include <stdio.h>
#include <string.h>
int main() {
char word[50];
int i = 0, length, t = 0, T = 0;
scanf("%s", word);
length = strlen(word);
t = word[i] == 't';
T = word[i] == 'T';
while(!t || !T) {
if((t || T) && i <= length / 2) {
printf("%d", '1');
} else if((t || T) && i > length / 2) {
printf("%d", '2');
//}else{
// printf("%d", '-1');
}
i++;
}
return 0;
}
If I enter any word and press enter, nothing is printed. Another thing is that when I remove the comment slashes from the two lines at the bottom, the program goes through an infinite loop.
Could someone please help?
This sounds like a school assignment, so I'll focus on advising/critiquing your code rather than giving a solution.
The first recommendation I have is to use a for loop instead of a while loop. A Rule of thumb in C is to only use a while loop when you actually don't have any idea how many things you need your program to look at.
You already have the length of the string, so set up your for loop to loop exactly once for each character.
Next you need to change how you are using printf. The %d format specifier is for printing integers, but you are passing it '1'. This is not an integer, it is the ascii representation of the symbol 1 (which is actually has the value 49, see the ascii table for more info)
You can either pass printf the value 1, or use the %c specifier, which expects ascii characters.
Better yet, just say printf("1");
That doesn't get you all the way there, but I think it lays the ground work so you can find the solution!
Condition !t || !T has no sense to be used as loop condition ...ask yourself how the loop will end ? you need just to check i is less than length
Second, the assignments t = word[i] == 't'; T = word[i] == 'T'; outside the loop have no sense ...you will be just pointing to the zero index of the string ...you should check all characters
third , the printf lines need to use %d
fourth , you appear not getting the purpose of the program printing inside loop will lead to printing many numbers and you just want to know if there is t or T you need to print single line.you may use variable int result=0; to hold the value you want and print it in the end ...of course you will need using break statement in the if((t || T) && i <= length / 2) and if((t || T) && i > length / 2) because no need for more searching
fifth, you should re-read , re-think , re-code the assignment before going bored and asking about it
sixth, there is a working version by modifying your code but you should try writing a good solution before looking at a solution as it better to solve your problems by yourself
#include <stdio.h>
#include <string.h>
int main() {
char word[50];
int i = 0, length, t = 0, T = 0;
scanf("%s", word);
length = strlen(word);
int result=0;
while( i<length) {
t = word[i] == 't';
T = word[i] == 'T';
if((t || T) && i <= length / 2) {
result=1;
break;
} else if((t || T) && i > length / 2) {
result=2;
break;
}else{
result=-1;
}
i++;
}
printf("%d",result);
return 0;
}
# include <stdio.h>
int main()
{
char name[20];
int age;
int siblings;
int childrens;
printf ("Hello my name is A.I, what is your name? \n");
scanf("%s", &name);
printf("how old are you : \n");
scanf("%d",&age);
printf("how many siblings you have: \n");
scanf("%d", &siblings);
printf("how many children you have: \n");
scanf("%d", &childrens);
printf("so your name is : %s \n", name);
printf("and your age is : %d \n", age);
printf("you have siblings : %d\n", siblings);
printf("so you have childrens : %d\n", childrens);
return 0;
}
im new to c i try to make a little and very simple game of hangedman and i dont know why doesent work get error in gcc "expected declaration or statement at the end of input"
im new to c and ii try very hard to learn it.
im missing something? my function is not right? some advice to learn alghorytmically thinking?
thanx in advance for the hel you gonna give me
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//function to find letter in string
int findletter(char y)
{
char c;
int i;
char secret[] = "outcast";
i = 0;
scanf("%c", &c);
while (c != secret[i] && i < strlen(secret))
i++;
if(c == secret[i])
return (1);
else
return (0);
}
//confirmation letter
int guessed(char a)
{
int z;
char guess [6] = {0};
z = 0;
while(findletter(guess[z]) != 1 && findletter(guess[z]) < 6)
{
z++;
if(findletter(guess[z]) == 1)
return 1;
else
return 0;
//word guessed
int tryguess(char v)
{
int x;
x = 0;
while(findletter(guess[x]) == 0)
{
x++;
if(findletter(guess[x] == 1))
return 1;
else
return 0;
}
}
int main()
{
char secret[] = "outcast";
char letter;
int lives;
char guess [6] = {0};
int i;
lives = 10;
i = 0;
printf("welcome to the hanged man\n");
while(i < 6)
{
if((findletter(secret[i] == 1)))
printf("%c", secret[i]);
else
printf("*\n");
i++;
}
return 0;
}
Correction to your code...
int guessed(char a)
{
int z;
char guess [6] = {0};
z = 0;
while(findletter(guess[z]) != 1 && findletter(guess[z]) < 6)
{
z++;
if(findletter(guess[z]) == 1)
return 1;
else
return 0;
} // you forgot closing while loop here
} // function closing parenthesis
//word guessed
Advice:
I don't know how much you had practice and how much you had learned yet..but on observing your mistake above I would like to suggest that whenever you create function or loop always write its prototype first, let's say you want to create a function for adding two numbers..
STEP 1: write prototype
int add(int x, int y)
{
//then do your stuff here...
return 0;
}
This will eliminate you chances of making error of parentheses...
There are a lot of issues with this program, from both a syntax standpoint and a logical one.
General issues include:
Function guessed and its while loop are not closed (missing }).
There is a lot of unused code (functions and variables).
The line if((findletter(secret[i] == 1))) compares the character value of secret[i] with 1 and passes that result to findletter. This doesn't matter though since you don't use this argument, and take user input within the function.
You have hardcoded strings and lengths, which makes your program less dynamic and harder to change in the future.
Using while loops as guards (in the unused functions tryguess and guessed), that are always exited on the first iteration.
findletter simply checks if secret contains the character c, returning on the first occurrence.
It could be more clearly expressed as:
int findletter(char unused) {
char secret[] = "secret",
c;
scanf(" %c", &c);
for (size_t i = 0; i < strlen(secret); i++)
if (secret[i] == c)
return 1;
return 0;
}
With that said, findletter would be better if you passed both the secret and c as arguments, so that you can use it more generically, and decouple user input from the function itself.
(Or you could simply use the standard library function strchr which achieves a very similar goal.)
The pattern of
if (a == b)
return 1;
else
return 0;
can simply be reduced to
return a == b;
Aside from the issues above, the structure of your program doesn't make much sense. If our program worked, you'd basically be asking the player to guess a word of unknown length, one character of the word at a time. They can also simply guess any letter to display the current one. One could 'solve' the entire word "secret" by simply inputting 's' repeatedly.
The structure of a very basic hangman program is:
Select the word to be guessed. Select number of lives.
Create a blanked version of word to track progress. Display this blanked version, which indicates the length to the player.
Ask the player to guess a letter. Skip those already guessed.
Update all positions in the blanked version where letter appears in the word.
Decrement lives on miss, end game if out of lives.
Check if the amount of characters changed in the blank version matches the length of word.
Win condition, or return to step 3.
There are many different ways to achieve this, and there are likely thousands of examples online.
Here is a rough program that is about as simple as it gets. This showcases the usual structure and flow of a game of hangman.
#include <stdio.h>
#include <string.h>
size_t update_all(char *to, const char *from, size_t len, char g) {
size_t changed = 0;
for (size_t i = 0; i < len; i++)
if (from[i] == g) {
to[i] = g;
changed++;
}
return changed;
}
void play_hangman(const char *word, unsigned lives) {
size_t word_length = strlen(word),
blanked_length = 0;
char blanked[word_length + 1],
guess = '\0';
for (size_t i = 0; i < word_length; i++)
blanked[i] = '*';
blanked[word_length] = '\0';
while (lives) {
printf("The word: [%s]\n"
"(Lives = %u) Enter a guess: ",
blanked,
lives);
scanf(" %c", &guess);
if (strchr(blanked, guess)) {
printf("[%c]: Already guessed!\n", guess);
continue;
}
size_t found = update_all(blanked, word, word_length, guess);
blanked_length += found;
if (!found) {
printf("[%c]: NOT FOUND!\n", guess);
lives--;
} else
printf("[%c]: FOUND!\n", guess);
if (!lives)
puts("Out of lives! You lose!");
else if (blanked_length == word_length) {
printf("You win! Word is [%s].\n", word);
return;
}
}
}
int main(void) {
play_hangman("secret", 10);
}
Note that this program is far from perfect, as it doesn't fully keep track of guessed letters, so the player can guess the same wrong letter multiple times, and lose a life every time. To fix this, we would need even more state, collecting each guess the player makes, and use that data instead of the naive if (strchr(blanked, guess)).
It also makes use of the '*' character as a sentinel value, which would cause confusion if our word contained '*'. To fix this, we could use an array of boolean values indicating the correctly guessed letters in the word thus far, and use this to print our word character-by-character. Or we could restrict character inputs with functions like isalpha.
This program simply serves as an example that for a proper approximation of the typical "Hangman" you need to handle more game state than you have.
(Error handling omitted for brevity throughout this answer.)
So I have a question, I was asked to encrypt a word using ASCII, with the following parameters
Input
12 2 //16 is the number of words , 2 is the subtraction number for the decimal form of the word
Good Morning // the words, spaces are not encrypted
Output
Gmob Mmrlilg // only 2 multiply of characters are encrypted
I have tried to make the decimal subtraction program first and not considering the space. But its error on pointer values
I have tried this
#include<stdio.h>
#include<string.h>
#include<math.h>
int x,y,dec_ofletter;
char a;
char z[100];
char w[100];
char encrypt(int x,int y, char *z){
int i;
int h=strlen(z);
for(i=0;i<h;i++){
if(i%2==0){
dec_ofletter=z[i]
dec_ofletter = dec_ofletter-y;
}
z[i]=dec_ofletter;
}
return z;
}
int main(void)
{
scanf("%d %d",&x,&y);
scanf("%99[^\n]",z);
a=encrypt(x,y,z);
printf("%s",a);
return 0;
}
But it getting error. In console it say
main.c:16:20: error: indirection requires pointer operand
('int' invalid)
dec_ofletter=*z[i]
^~~~~
main.c:19:3: error: indirection requires pointer operand
('int' invalid)
*z[i]=dec_ofletter;
^~~~~
thanks for your kind help
update the pointer problem is solved , but di output is like this
12 2 Good Morning //input
exited, segmentation fault //output
Is the logic of my program wrong?
Have added a flag to ensure purposed entry into the correct conditional.
The logic employed is
1 Start the counter int i at one.
since you are attempting to replace every second non-space character
from the array.
And to control the flow of the conditionals that follow.
2.Check if the character is space,
if yes check if the counter is even or odd.
If even or odd set the flag accordingly and continue(since spaces are not encrypted).
3.The following ifs update the array based on odd/even positions and the flag which was in the first if.
In addition,
am returning the character pointer (char *) received in the encrypt function
back to main.
Have removed the global variable dec_ofletter since it is not
required in operations.
The code should, hopefully, be able to handle leading and multiple spaces in between words.
Putting it together, this is the code......
#include<stdio.h>
#include<string.h>
int x,y;
char a;
char z[100];
char w[100];
char * encrypt(int x,int y, char *z){
int i;
int flag = 1;//set flag at beginning
int h=strlen(z);
for(i = 1;i<h;i++){//set counter at 1
if(z[i] == ' '){ //If space
if(i % 2 == 1){ //counter is odd
flag = 1; //set flag
continue;
}
if(i % 2 == 0){//If even
flag = 0; //clear flag
continue;
}
}
if(i%2==1 && flag == 1)//select odd based on flag
z[i] = z[i] - y;//update array
if(i%2 == 0 && flag == 0)//select even based on flag
z[i] = z[i] - y;//update array
}
return z;
}
int main(void)
{
scanf("%d %d",&x,&y);
getchar();
scanf("%99[^\n]",z);
encrypt(x,y,z);
printf("%s",z);
return 0;
}
This is the problem I'm trying to solve:
Input:
First line contains N, the size of the string.
Second line contains the letters (only lowercase).
Output:
Print YES if all vowels are found in the string, NO otherwise.
Constraints:
The size of the string will not be greater than 10,000. 1 ≤ N ≤ 10000
The following code I wrote is always showing NO.
#include <stdio.h>
#include<conio.h>
int main()
{
int a,b,c=0,d=0,e=0,f=0,g=0,i;
char string[10000];
scanf("%d",&a);
scanf("%s",string);
for(i=0;i<a;a++)
{
if(string[i]==('a'))
c=1;
if(string[i]==('e'))
d=1;
if(string[i]==('i'))
e=1;
if(string[i]==('o'))
f=1;
if(string[i]==('u'))
g=1;
}
if((c==1)&&(d==1)&&(e==1)&&(f==1)&&(g==1))
printf("YES");
else
printf("NO");
return 0;
getch ();
}
Here is an infinite loop that causes a problem:
for(i=0;i<a;a++)
You should increment i, instead of a (length of a string). If you fix this one char in loop statement, the program will run well at all. Anyway, I changed your code a bit to be more readable. Take a look if you want, just for your information, sir:
#include <stdio.h>
#include <stdlib.h>
int main()
{
int len, a=0, e=0, i=0, o=0, u=0, it;
char string[10000];
scanf("%d", &len);
scanf("%s", string);
for(it=0;it<len;it++)
{
if(string[it]=='a') a = 1;
else if(string[it]=='e') e = 1;
else if(string[it]=='i') i = 1;
else if(string[it]=='o') o = 1;
else if(string[it]=='u') u = 1;
}
if(a && e && i && o && u) printf("YES\n");
else printf("NO\n");
system("PAUSE");
return 0;
}
I assume you are running your program under Windows, so instead of conio's getch() try to use system("PAUSE") or just even better way to do this (for both Windows for UNIX): getchar()
I've renamed all of your variables, but otherwise left the code the same.
#include <stdio.h>
#include<conio.h>
int main()
{
int foundA = 0, foundE = 0, foundI = 0, foundO = 0, foundU = 0;
int i, length;
char string[10000];
scanf("%d", &length);
scanf("%s", string);
for(i=0; i<length; length++)
{
if(string[i]==('a'))
foundA=1;
else if(string[i]==('e'))
foundE=1;
else if(string[i]==('i'))
foundI=1;
else if(string[i]==('o'))
foundO=1;
else if(string[i]==('u'))
foundU=1;
}
if((foundA==1)&&(foundE==1)&&(foundI==1)&&(foundO==1)&&(foundU==1))
printf("YES");
else
printf("NO");
return 0;
getch ();
}
Looking the the for-loop condition for(i=0; i<length; length++), I think it's pretty clear what's wrong. Instead of incrementing the counter, you're incrementing the length of the string. Eventually, the counter overflows to a negative number, and the loop terminates without ever looking at a character besides the first one. The lesson here is to name your variables properly.
If you want to be picky, then signed integer overflow is undefined behavior, but for most systems, INT_MAX + 1 will be INT_MIN.
This program can be done in more simpler way other as below.
#include <stdio.h>
#include<conio.h>
int main()
{
int i, flag = 0;
char string[10000], *ptr;
char cmp[] = "aeiou";
printf("Please enter string = " );
scanf("%s", string);
i = 0;
while(cmp[i])
{
ptr = string;
while(*ptr)
{
if(cmp[i] == *ptr)
break;
ptr++;
}
if(*ptr != cmp[i++])
{
flag = 1;
break;
}
}
if(flag == 1)
printf("NO");
else
printf("YES");
}
In this program I have used just one flag instead of 5 flags. Always try to write simple code rather then using unnecessary variable and flags.
I am trying to write a program that adds, subtracts, multiplies, and divides a string of characters. Where I'm at now with the program is figuring out how to split the input string into two strings, and then perform the appropriate +-/*.
The input should look like this abc+aaa
and the output for that should be abc + aaa = bcd
How do I convert character strings into integer strings?
#include <stdio.h>
#include <math.h>
#include <string.h>
int main() {
printf("This is a pseudo arithmetic program");
char input[10];
input[10] = '\0';
char first [9];
first[9] = '\0';
char last [9];
last[9] = '\0';
int i = 0;
int b;
int e;
while (input[0] != '0') {
if (input[0] == 0){
return -1;
}
printf("\nEnter a math problem in SOS format using only lowercase letters up to 9 characters");
printf("\nEx: abc+abc... type '0' to quit \n");
scanf("%s", input);
int x = 0;
x = strlen(input);
if (strchr(input, '+')){
for (i = 0; i <= x; i++) {
if (i == '+')
strncpy(first, &input[0], i-1);
i = 0;
}
for (i = x; i >= input[0]; i--) {
if (i == '+')
strncpy(last, &input[i], x);
i = 0;
}
printf("%s", first);
printf(" + ");
printf("%s", last);
printf(" = %d", first + last);
}
There seems to be multiple problems with your code:
There is a array out of bounds happening for almost all the arrays:
char input[10];
input[10] = '\0';
In this if you want to initialize the last character with '\0' then it should be
input [9] = '\0'
Arrays indexes always start from 0.
It is not clear what is the use of below lines:
while (input[0] != '0') { if (input[0] == 0){ return -1; }
When taking input for a string, why are prompting users to enter a 0 to end it?
strrchr returns the pointer from where the searched character begins. So, you can that itself to determine where the '+' symbol is and two split the strings instead of your while loop. See strrchr man page
Also, your idea of adding characters is not clear. From your example, it appears you are considering a = 1, b = 2 etc. In such a case, if your code is case insensitive, then you can convert all your input to upper case and then do (input[0] - 'A')+1 to convert your letters like a, b, c to 1, 2, 3 etc.
Hope these pointers help. Suggest you check your problem statement again and refactor your code accordingly.