Interview question -- output the same characters in two character arrays

#include<iostream>
using namespace std;

void FindCommonChar(char a[], int lena, char b[], int lenb)
{
    int hasha[256] = {0};
    int hashb[256] = {0};
    for (int i = 0; i < lena; i++)
    {
        hasha[(int)a[i]] = 1;
    }
    for (int j = 0; j < lenb; j++)
    {
        hashb[(int)b[j]] = 1;
    }

    for (int i = 0; i < 256; i++)
    {
        if (hasha[i] == 1 && hashb[i] == 1)
        {
            std::cout << (char)i << std::endl;;
        }
    }
}

int main()
{
    char a[5] = {'1', 'b', 'C', 'f', 'f'};
    char b[6] = {'1', 'b', 'd', 'e', 'C','d'};
    FindCommonChar(a, 5, b, 6);
    return 0;
}