#include <stddef.h>
#include <stdint.h>
#include <string.h>

int memcmp(const void *vl, const void *vr, size_t n) {
    const unsigned char *l = vl, *r = vr;
    for (; n && *l == *r; n--, l++, r++);
    return n ? *l-*r : 0;
}

void *memcpy(void *restrict dest, const void *restrict src, size_t n) {
    char *d = dest;
    const char *s = src;
    for (; n; n--) *d++ = *s++;
    return dest;
}

void *memmove(void *dest, const void *src, size_t n) {
    char *d = dest;
    const char *s = src;

    if (d==s) return d;

    if (d<s) {
        for (; n; n--) *d++ = *s++;
    } else {
        while (n) n--, d[n] = s[n];
    }

    return dest;
}

void *memset(void *dest, int c, size_t n) {
    unsigned char *d = dest;
    for (; n; n--) *d++ = c;
    return dest;
}

char *strcpy(char *restrict dest, const char *restrict src) {
	for(; (*dest = *src); dest++, src++);
	return dest;
}

char *strncpy(char *restrict dest, const char *restrict src, size_t n) {
	for(; (*dest = *src) && n; dest++, src++, n--);
	memset(dest, 0, n);
	return dest;
}

size_t strlen(const char *s) {
    size_t len = 0;
    for(; *s; s++, len++);
    return len;
}

int strncmp(const char* lhs, const char* rhs, size_t n) {
	const unsigned char *l=(void *)lhs, *r=(void *)rhs;
	if (!n--) return 0;
	for (; *l && *r && n && *l == *r ; l++, r++, n--);
	return *l - *r;
}