Count Paths Queries

/*
+---------------------------------------------+
|                                             |
|  Copytright, MinaMagdy, 11/04/2023 (01:24)  |
|                                             |
+---------------------------------------------+
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define multi_ordered_set tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
#define endl "\n"
#define MOD 1000000007
#define INF 2000000000
#define all(s) s.begin(), s.end()
#define rall(s) s.rbegin(), s.rend()
#define sz(x) int(x.size())

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
#include <ext/numeric>
using namespace __gnu_cxx;
typedef vector<vector<int>> matrix;
struct mul {
    int n;
    int mod;
    mul(int n, int mod = 1e9 + 7) : n(n), mod(mod) {}
    matrix operator()(const matrix &a, const matrix &b) {
        matrix c(n, vector<int>(n, 0));
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                for (int k = 0; k < n; k++) {
                    c[i][j] += a[i][k] * 1ll * b[k][j] % mod;
                    if (c[i][j] >= mod)
                        c[i][j] -= mod;
                }
            }
        }
        return c;
    }
};

matrix identity_element(const mul &m) {
    matrix res(m.n, vector<int>(m.n, 0));
    for (int i = 0; i < m.n; i++)
        res[i][i] = 1;
    return res;
}
void solve() {
    int n, m, q;
    cin >> n >> m >> q;
    matrix a(n, vector<int>(n, 0));
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        a[u][v] = 1;
    }
    map<int, matrix> mp;
    while (q--) {
        int s, e, k;
        cin >> s >> e >> k;
        s--, e--;
        if (!mp.count(k))
            mp[k] = power(a, k, mul(n));
        cout << mp[k][s][e] << endl;
    }
}

int main(void)
{
    ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
    int testcase = 1;
    // cin >> testcase;
    while (testcase--)
        solve();
    return 0;
}