Peli

#include <bits/stdc++.h>
using namespace std;
#define rall(x) x.rbegin(),x.rend()
#define all(x) x.begin(),x.end()
using ll = long long;

const int N = 2501;
vector<int> adj[N];
bool vis[N][2];
int dist[N][N][2];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int n, m, q;
    cin >> n >> m >> q;

    while (m--) {
        int a, b;
        cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    for (int i = 1; i <= n; i++) {

        memset(vis, 0, sizeof(vis));

        queue<pair<int, bool>> bfs;
        bfs.push({i, true});
        vis[i][true] = true;

        for (int j = 1; j <= n; j++) dist[i][j][true] = dist[i][j][false] = 1e9;
        dist[i][i][true] = 0;

        while (!bfs.empty()) {
            auto u = bfs.front();
            bfs.pop();
            for (int v : adj[u.first]) {
                if (vis[v][!u.second]) continue;
                vis[v][!u.second] = true;
                dist[i][v][!u.second] = dist[i][u.first][u.second] + 1;
                bfs.push({v, !u.second});
            }
        }

    }


    while (q--) {
        int a, b, x;
        cin >> a >> b >> x;
        cout << (dist[a][b][x % 2 == 0] <= x ? "YES\n" : "NO\n");
    }
    
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 2

Verdict: ACCEPTED

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 1, 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED