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

void *ft_memchr(const void *s, int c, size_t n)
{
    const unsigned char *p = s;
    unsigned char uc = (unsigned char)c;

    while (n && ((uintptr_t)p % sizeof(size_t))) {
        if (*p == uc)
            return ((void *)p);
        ++p;
        --n;
    }
    size_t mask = 0;
    for (size_t i = 0; i < sizeof(size_t); ++i)
        mask |= (size_t)uc << (i * 8);

    while (n >= sizeof(size_t)) {
        size_t word = *(const size_t *)p;
        size_t cmp = word ^ mask;
        for (size_t i = 0; i < sizeof(size_t); ++i) {
            if (((cmp >> (i * 8)) & 0xFF) == 0)
                return ((void *)(p + i));
        }
        p += sizeof(size_t);
        n -= sizeof(size_t);
    }
    while (n--) {
        if (*p == uc)
            return ((void *)p);
        ++p;
    }
    return (NULL);
}