C 标准库 strcmp 函数的实现

/*
 * strcmp 字符串的比较
 */

#include <cstdio>

int strcmp ( const char * str1, const char * str2 ) {
    while (*str1==*str2 && *str1!='\0')
        ++str1, ++str2;

    return *str1-*str2;
}

int main ()
{
    char key[] = "apple";
    char buffer[80];
    do {
        printf ("Guess my favorite fruit? ");
        fflush (stdout);
        scanf ("%79s",buffer);
    } while (strcmp (key,buffer) != 0);
    puts ("Correct answer!");
    return 0;
}