Cod sursă (job #239278)

#include <fstream>

using namespace std;

ifstream fin ("fotografie.in");
ofstream fout ("fotografie.out");

#define MAX 1002
#define mod 46103

char a[MAX][MAX], b[MAX][MAX];
int nr[MAX], mx, my, mz, p, q, m, n, sm, val;

void ok(int x, int y)
{
    for (int i = x; i > x - p; -- i)
        for (int j = y; j > y - q; -- j)
            if (a[i][j] != b[i - (x - p + 1)][j - (y - q + 1)])
                return ;
    fout << x - p + 1 << ' ' << y - q + 1 << '\n';
}

int main()
{
    fin >> n >> m;
    for (int i = 0; i < n; ++ i)fin >> a[i];

    fin >> p >> q;
    for (int i = 0; i < p; ++ i)fin >> b[i];

    for (int j = 0; j < q; ++ j)
        for (int i = 0; i < p; ++ i)
            sm = (sm * 26 + (b[i][j] - 'a')) % mod;

    mx = 1;
    my = 1;
    mz = 1;
    for (int i = 1; i < p; ++ i)mx = (mx * 26) % mod;

    mz = (mx * 26) % mod;
    for (int i = 1; i < q; ++ i)my = (my * mz) % mod;

    for (int j = 0; j < m; ++ j)
        for (int i = 0; i < p - 1; ++ i)
            nr[j] = (nr[j] * 26 + (a[i][j] - 'a')) % mod;

    for (int i = p - 1; i < n; ++ i)
    {
        for (int j = 0; j < m; ++ j)
            nr[j] = (nr[j] * 26 + (a[i][j] - 'a')) % mod;

        val = 0;
        for (int j = 0; j < q - 1; ++ j)
            val = (val * mz + nr[j]) % mod;

        for (int j = q - 1; j < m; ++ j)
        {
            val = (val * mz + nr[j]) % mod;
            if (val == sm)ok(i, j);

            val = ((val - my * nr[j - q + 1]) % mod);
            if (val < 0)val += mod;
        }

        for (int j = 0; j < m; ++ j)
        {
            nr[j] = (nr[j] - mx * (a[i - p + 1][j] - 'a')) % mod;
            if (nr[j] < mod)nr[j] += mod;
        }
    }

    fin.close();
    fout.close();
    return 0;
}