Q343: What Base Is This ?

// Run time: 0.010
#include <stdio.h>
#include <string.h>
int find(int *num, int len);
int calculate(int *num, int len, int base);

int main()
{
    char str1[100], str2[100];
    int arr1[100], arr2[100];
    int len1, len2;
    int i; // base1
    int j; // base2
    int x, y;
    int m1, m2;
    while (scanf("%s%s", str1, str2) == 2)
    {
        len1 = strlen(str1);
        len2 = strlen(str2);

        for ( i = 0; i < len1; i++)
        {
            if (str1[i] >= '0' && str1[i] <= '9')
                arr1[i] = int(str1[i])-48;
            else
                arr1[i] = str1[i]- 'A' + 10;
        }
        for ( i = 0; i < len2; i++)
        {
            if (str2[i] >= '0' && str2[i] <= '9')
                arr2[i] = int(str2[i])-48;
            else
                arr2[i] = str2[i] - 'A' + 10;
        }

        m1 = find(arr1, len1);
        m2 = find(arr2, len2);

  //    printf("m1: %d, m2: %d\n", m1, m2);

        bool state = false;
        for ( i = m1; i <= 36; i++)
        {
            for ( j = m2; j <= 36; j++)
            {
                x = calculate(arr1, len1, i);
                y = calculate(arr2, len2, j);

                if (x < y)
                    break;
                else
                if (x == y)
                {
                    state = true;
                    break;
                }
            }

            if (state)
                break;
        }
        if (!state) // no one can equal
            printf("%s is not equal to %s in any base 2..36\n", str1, str2);
        else
            printf("%s (base %d) = %s (base %d)\n", str1, i, str2, j);

    }

    return 0;
}

int find(int *num, int len)
{
    if (len == 1 && (num[0] == 0 || num[0] == 1))
        return 2;
    int i;
    int max = num[0];
    for ( i = 1; i < len; i++)
    {
        if (num[i] > max)
            max = num[i];
    }
    return max+1;

}

int calculate(int *num, int len, int base)
{
    int i;
    int sum = 0;
    int weight = 1;

    for ( i = len-1; i >= 0; i--)
    {
        sum += num[i]*weight;
        weight *= base;
    }

    return sum;
}