Luogu_P_5663.cpp

#include <bits/extc++.h>
using namespace std;
namespace pbds = __gnu_pbds;
using ui = unsigned int;
using uli = unsigned long long int;
using li = long long int;
using graph = vector<vector<size_t>>;
int main(void) {
  ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
  size_t n, m, t;
  cin >> n >> m >> t;
  graph mp(n);
  while (m--) {
    size_t u, v;
    cin >> u >> v;
    --u, --v;
    mp[u].push_back(v), mp[v].push_back(u);
  }
  vector<size_t> dist[2];
  dist[0].resize(n), dist[1].resize(n);
  fill(dist[0].begin(), dist[0].end(), -1),
      fill(dist[1].begin(), dist[1].end(), -1);
  dist[0][0] = 0;
  queue<pair<size_t, size_t>> q({
      {0, 0}
  });
  while (!q.empty()) {
    pair<size_t, size_t> p = q.front();
    q.pop();
    for (size_t const i : mp[p.first])
      if (!~dist[p.second & 1 ^ 1][i])
        dist[p.second & 1 ^ 1][i] = p.second + 1, q.emplace(i, p.second + 1);
  }
  while (t--) {
    size_t a, l;
    cin >> a >> l;
    cout << (dist[l & 1][--a] <= l ? "Yes\n" : "No\n");
  }
  return 0;
}