A story with strings

There was a competition here http://www.codechef.com/MARCH14 and there was a problem A story with strings I solved it and want to know if it is successful

#include <iostream>
#include <string>
#include <vector>

using namespace std;

struct Hash
{
    string s;
    int H;
};

int main()
{
    string s1, s2;
    getline(cin, s1);
    getline(cin, s2);
    vector<Hash> H1(s1.size() * s1.size());
    vector<Hash> H2(s2.size() * s2.size());
    int k1 = 0;
    int k2 = 0;
    for(int i = 0; i < s1.size(); ++i)
    {
        int HforH1 = s1[i];
        H1[k1].H = s1[i];
        H1[k1].s = s1[i];
        ++k1;
        for(int j = i + 1; j < s1.size(); ++j)
        {
            HforH1 += s1[j] * 19 + s1[j - 1];
            H1[k1].H = HforH1;
            H1[k1].s = s1.substr(i, j - i + 1);
            ++k1;
        }
    }
    for(int i = 0; i < s2.size(); ++i)
    {
        int HforH2 = s2[i];
        H2[k2].H = s2[i];
        H2[k2].s = s2[i];
        ++k2;
        for(int j = i + 1; j < s2.size(); ++j)
        {
            HforH2 += s2[j] * 19 + s2[j - 1];
            H2[k2].H = HforH2;
            H2[k2].s = s2.substr(i, j - i + 1);
            ++k2;
        }
    }
    Hash maxOf2;
    maxOf2.H = H1[0].H;
    maxOf2.s = H1[0].s;
    for(int i = 0; i < H1.size(); ++i)
        for(int j = 0; j < H2.size(); ++j)
        {
            if(H1[i].H == H2[j].H)
            {
                if(H1[i].H > maxOf2.H)
                {
                    maxOf2.H = H1[i].H;
                    maxOf2.s = H1[i].s;
                }
            }
        }
    cout << maxOf2.s.size() << endl << maxOf2.s << endl;
}

this is the solution for getline(cin, string)