/*基本算法实现*/Linux中string.h里几个函数的实现

extern int strcmp(const char*,const char*);
extern char* strcpy(char*,const char*);

int strcmp(const char *cs, const char *ct)
{
    unsigned char c1, c2;

    while (1) {
        c1 = *cs++;
        c2 = *ct++;
        if (c1 != c2)
            return c1 < c2 ? -1 : 1;
        if (!c1)
            break;
    }
    return 0;
}

char *strcpy(char *dest, const char *src)
{
    char *tmp = dest;

    while ((*dest++ = *src++) != ‘\0‘)
        /* nothing */;
    return tmp;
}