#include "levenshtein.h"

#include <stdio.h>

size_t max(size_t a, size_t b)
{
    if (a >= b)
    {
        return a;
    }
    return b;
}

size_t min(size_t a, size_t b)
{
    if (a <= b)
    {
        return a;
    }
    return b;
}

size_t min_3(size_t a, size_t b, size_t c)
{
    if (a <= b)
    {
        if (a <= c)
        {
            return a;
        }
        return c;
    }
    else
    {
        if (b <= c)
        {
            return b;
        }
        return c;
    }
}

size_t my_strlen(const char *s)
{
    size_t i;
    for (i = 0; s[i]; i++)
    {
        continue;
    }
    return i;
}

size_t levenshtein(const char *s1, const char *s2)
{
    size_t l1 = my_strlen(s1);
    size_t l2 = my_strlen(s2);
    if (min(l1, l2) == 0)
    {
        return max(l1, l2);
    }

    if (s1[0] == s2[0])
    {
        return levenshtein(s1 + 1, s2 + 1);
    }

    size_t lev1 = levenshtein(s1 + 1, s2);
    size_t lev2 = levenshtein(s1, s2 + 1);
    size_t lev3 = levenshtein(s1 + 1, s2 + 1);

    return 1 + min_3(lev1, lev2, lev3);
}