#include int strcmp(const char *s1, const char *s2) { int i; for (i = 0; s1[i] == s2[i]; i++) { if (s1[i] == '\0') { return 0; } } return s1[i] - s2[i]; } int strncmp(const char *s1, const char *s2, size_t n) { for (; n > 0; s1++, s2++, --n) { if (*s1 != *s2) { return ((*(unsigned char *)s1 < *(unsigned char *)s2) ? -1 : 1); } else if (*s1 == '\0') { return 0; } } return 0; }