func_code_string: #include <bits/stdc++.h>   const int INF_INT = 0x3f3f3f3f;   const long long INF_LL = 0x7f7f7f7f;   const int MOD = 1e9 + 7;   const double eps = 1e-10;   const double pi = acos(-1);   using namespace std;   const int N = 200200;   int n, m, q;   int u[N], v[N];   struct Query {     int l, r, s, t, id;     Query(int l, int r, int s, int t, int id) : l(l), r(r), s(s), t(t), id(id) {}     Query() {}     bool operator<(const Query& rhs) const { return l > rhs.l; }   };   vector<Query> qs;   int dp[1010][1010];   int ans[N];   int main(int argc, char const* argv[]) {     scanf( %d%d%d , &n, &m, &q);     for (int i = 1; i <= m; i++) scanf( %d%d , &u[i], &v[i]);     for (int i = 1; i <= q; i++) {       int l, r, s, t;       scanf( %d%d , &l, &r);       scanf( %d%d , &s, &t);       qs.emplace_back(l, r, s, t, i);     }     sort(qs.begin(), qs.end());     memset((dp), (INF_INT), sizeof(dp));     for (int i = 1; i <= n; i++) dp[i][i] = 0;     int cnt = 0;     for (int i = m; i >= 1; i--) {       dp[u[i]][v[i]] = dp[v[i]][u[i]] = i;       for (int j = 1; j <= n; j++) {         if (j != u[i]) dp[v[i]][j] = min(dp[v[i]][j], dp[u[i]][j]);         if (j != v[i]) dp[u[i]][j] = min(dp[u[i]][j], dp[v[i]][j]);       }       while (cnt < qs.size() && qs[cnt].l >= i) {         ans[qs[cnt].id] = dp[qs[cnt].s][qs[cnt].t] <= qs[cnt].r;         cnt++;       }     }     for (int i = 1; i <= q; i++) puts(ans[i] ?  Yes  :  No );     return 0;   }   