C equivalent function

Question

I'm working on a task to convert

void f(char s[], char t[]){   
    int k=0;
        while (s[k]=t[k])  k++; 
} 

into the equivalent form of

void f(char *s, char *t)
{    
    while (____);
}

I know it can be converted to

void f(char *s, char *t){
    int k=0;
    while (*(s+k)=*(t+k))k++;
}

The problem is, it is only allowed to fill in the bracket. I am running out of idea

Answer 1

Simply increment the pointers themselves.

void f(char *dest, char *source) {
    while ((*dest++ = *source++));
}

This will end the loop when the assigned character is NUL ('\0').

Example program, with type qualifier correctness:

#include <stdio.h>

void f(char *dest, const char *source) {
    while ((*dest++ = *source++));
}

int main(void) {
    char buffer[32];
    const char *string = "Hello, world!";
    f(buffer, string);
    puts(buffer);
}

Of course, this has the same issues as the standard library strcpy, you must be careful to make sure there is enough space in your destination buffer before calling this function.