#include "my_strspn.h"

int is_in(char c, const char *accept)
{
    for (; *accept && *accept != c; accept++)
    {
        continue;
    }
    return *accept != '\0';
}

size_t my_strspn(const char *s, const char *accept)
{
    if (s == NULL || *s == '\0')
    {
        return 0;
    }

    size_t res;
    for (res = 0; *s && is_in(*s, accept) != 0; res++, s++)
    {
        continue;
    }

    return res;
}