Peli

input/code.cpp: In function 'void bfs(const vvl&, ll, std::vector<std::vector<std::vector<long long int> > >&, vl&, std::queue<std::pair<std::pair<long long int, long long int>, long long int> >)':
input/code.cpp:53:34: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   53 |                             auto [u, v] = xq.front();
      |                                  ^
input/code.cpp:21:17: warning: unused variable 'j' [-Wunused-variable]
   21 |     ll i, node, j;
      |                 ^
input/code.cpp: In function 'int main()':
input/code.cpp:142:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  142 |         auto [u, v] = x.front();
      |              ^

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector <ll> vl;
typedef vector <vl> vvl;
typedef pair <ll, ll> pl;
typedef vector <pl> vpl;
typedef vector <bool> vb;

const ll inf = 1e18;
const ll mod = 1e9 + 7;
const ll nmax = 1e6;

#define fi first
#define se second
#define mp make_pair
#define pb push_back

void bfs(const vvl &g, ll n, vector <vvl> &m, vl &parent, queue <pair <pl, ll>> xq)
{
    ll i, node, j;
    queue <ll> q;
    q.push(1);

    while(!q.empty())
    {
        node = q.front();
        q.pop();
        for(auto x : g[node])
        {
            if(x != parent[node])
            {
                parent[x] = node;
                //ll t = node;
                //while(x != 0)
                //{
                    bool change = false;
                    for(i = 1; i <= n; i++)
                    {
                        if(m[0][node][i] != inf && m[1][x][i] > m[0][node][i] + 1)
                        {
                            m[1][x][i] = m[1][i][x] = m[0][node][i] + 1;
                            change = true;
                        }
                        if(m[1][node][i] != inf && m[0][x][i] > m[1][node][i] + 1)
                        {
                            m[0][x][i] = m[0][i][x] = m[1][node][i] + 1;
                            change = true;
                        }

                        while(!xq.empty())
                        {
                            auto [u, v] = xq.front();
                            if(m[v % 2][u.fi][u.se] != inf)
                                xq.pop();
                            else
                                break;
                        }
                        if(xq.empty())
                            return;
                    }
                    if(change)
                        q.push(x);
                    else
                        break;
                    //node = x;
                    //x = parent[x];
                //}
                //node = t;
            }

        }
    }

    /*for(ll i = 1; i <= n; i++)
    {
        cerr << i << ": ";
        for(ll j = 1; j <= n; j++)
            cerr << m[0][i][j] << " ";
        cerr << "\n";
    }
    cerr << "\n";
    for(ll i = 1; i <= n; i++)
    {
        cerr << i << ": ";
        for(ll j = 1; j <= n; j++)
            cerr << m[1][i][j] << " ";
        cerr << "\n";
    }*/

}

/*4 5 6
1 2
2 3
1 3
2 4
3 4
1 2 2
1 4 1
1 4 5
2 2 1
2 2 2
3 4 8*/

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    ll n, t, q, i, a, b, k;
    pl ans;
    cin >> n >> t >> q;
    vvl g(n + 1);
    vpl minn(n + 1, {inf, inf});
    vl parent(n + 1, 0);
    queue <pair <pl, ll>> x;
    vector <vvl> m(2, vvl(n + 1, vl(n + 1, inf)));
    for(i = 1; i <= n; i++)
        m[0][i][i] = 0;

    for(i = 0; i < t; i++)
    {
        cin >> a >> b;
        g[a].pb(b);
        g[b].pb(a);
    }

    //bfs(g, n, m, parent);

    //cerr << "\n";

    while(q--)
    {
        cin >> a >> b >> k;
        x.push({{a, b}, k});
    }

    bfs(g, n, m, parent, x);
    while(!x.empty())
    {
        auto [u, v] = x.front();
        x.pop();
        //cerr << m[v % 2][u.fi][u.se] << " ";
        if(m[v % 2][u.fi][u.se] <= v)
            cout << "YES\n";
        else
            cout << "NO\n";
    }

    /*for(ll i = 1; i <= n; i++)
    {
        cerr << i << ": ";
        for(ll j = 1; j <= n; j++)
            cerr << m[0][i][j] << " ";
        cerr << "\n";
    }
    cerr << "\n";
    for(ll i = 1; i <= n; i++)
    {
        cerr << i << ": ";
        for(ll j = 1; j <= n; j++)
            cerr << m[1][i][j] << " ";
        cerr << "\n";
    }*/

    return 0;
}

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: WRONG ANSWER

Test 10

Group: 2

Verdict: ACCEPTED