How to put letter out of string? C language - c

Question

void getAvailableLetters(char lettersGuessed[], char availableLetters[])
is function that I need to create. It must use strings.
availableLetters are letters of alphabet
lettersGuessed are letters inserted by user
function is supposed to do this:
Available letters: abcdefghijklmnopqrstuvwxyz
Gimme a letter: (let's guess 'm')
Available letters: abcdefghijklnopqrstuvwxyz //all without letter m
Gimme a letter: (let's hess 'b')
Available letters: acdefghijklnopqrstuvwxyz //all without letters m & b
Any algorythms, advices, codes or smth what would help me to do it would be great.

Answer 1

Test this one out. The function char_replace() takes in the source string, the character to find and the string to replace the character (can be also one char). In your case, you pass "" (empty value) for the char to be replaced with, because you want to remove it. But the parameter might come in handy, so I included it.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char *char_replace(char *, char, char *);
int main(void) {
char input[4096] = "abcdefghijklmnopqrstuvwxyz";
char *signature = char_replace(input, 'a', "");
printf("%s\n", input);
return 0;
}
char *char_replace(char *str, char find, char *replace) {
char *ret=str;
char *wk, *s;
// string duplication
wk = s = strdup(str);
while (*s != 0) {
if (*s == find){
while(*replace)
*str++ = *replace++;
++s;
} else
*str++ = *s++;
}
*str = '\0';
free(wk);
// returning the result string
return ret;
}
This approach is counting on the input array of chars (string) to have enough space with 4096 allocated to it.

Answer 2

#include<stdio.h>
#include<string.h>
char availableLetters[27]={"abcdefghijklmnopqrstuvwxyz"},lettersGuessed[2];
void getAvailableLetters(char lettersGuessed[], char availableLetters[])
{
int i,flag=0;
for(i=0;availableLetters[i]!='\0';i++)
{
if(availableLetters[i]==lettersGuessed[0])
{
flag=1;
for(;availableLetters[i]!='\0';i++)
{
availableLetters[i]=availableLetters[i+1];
}
}
if(flag==1)
{
availableLetters[i-1]='\0';
break;
}
}
}
input()
{
printf("Gimme a letter:");
scanf("%c",&lettersGuessed[0]);
fflush(stdin); //deleting extra characters
lettersGuessed[1]='\0';
}
output()
{
printf("Available letters:");
puts(availableLetters);
}
main()
{
output();
input();
getAvailableLetters(lettersGuessed,availableLetters);
output();
input();
getAvailableLetters(lettersGuessed,availableLetters);
output();
}