Submission #486901

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Source Code Expand

/*
 * d.cc: D: 
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100000;
const int MAX_M = 100000;
const int MAX_K = 100000;

/* typedef */

struct UFT {
  int links[MAX_N], ranks[MAX_N], sizes[MAX_N];
  
  UFT() {}

  void clear(int n) {
    for (int i = 0; i < n; i++)
      links[i] = i, ranks[i] = sizes[i] = 1;
  }

  int root(int i) {
    int i0 = i;
    while (links[i0] != i0) i0 = links[i0];
    return (links[i] = i0);
  }

  int rank(int i) { return ranks[root(i)]; }
  int size(int i) { return sizes[root(i)]; }
  bool same(int i, int j) { return root(i) == root(j); }

  int merge(int i0, int i1) {
    int r0 = root(i0), r1 = root(i1);
    int mr;
    if (ranks[r0] == ranks[r1]) {
      links[r1] = r0;
      sizes[r0] += sizes[r1];
      ranks[r0]++;
      mr = r0;
    }
    else if (ranks[r0] > ranks[r1]) {
      links[r1] = r0;
      sizes[r0] += sizes[r1];
      mr = r0;
    }
    else {
      links[r0] = r1;
      sizes[r1] += sizes[r0];
      mr = r1;
    }
    return mr;
  }
};

struct Edge {
  int a, b;
  bool f;
};

struct Query {
  int op, a, b;
};

/* global variables */

UFT uft;
Edge es[MAX_M];
Query qs[MAX_K];
stack<bool> ans;

/* subroutines */

/* main */

int main() {
  int n, m, k;
  cin >> n >> m >> k;

  for (int i = 0; i < m; i++) {
    cin >> es[i].a >> es[i].b;
    es[i].a--, es[i].b--, es[i].f = true;
  }

  for (int i = 0; i < k; i++) {
    cin >> qs[i].op;
    if (qs[i].op == 0) {
      int j;
      cin >> j;
      j--;
      qs[i].a = es[j].a;
      qs[i].b = es[j].b;
      es[j].f = false;
    }
    else {
      cin >> qs[i].a >> qs[i].b;
      qs[i].a--, qs[i].b--;
    }
  }

  uft.clear(n);
  
  for (int i = 0; i < m; i++)
    if (es[i].f) {
      int ra = uft.root(es[i].a);
      int rb = uft.root(es[i].b);
      if (ra != rb) uft.merge(ra, rb);
    }

  for (int i = k - 1; i >= 0; i--) {
    int ra = uft.root(qs[i].a);
    int rb = uft.root(qs[i].b);
    if (qs[i].op == 0) {
      if (ra != rb) uft.merge(ra, rb);
    }
    else {
      ans.push(ra == rb);
    }
  }

  while (! ans.empty()) {
    bool f = ans.top(); ans.pop();
    cout << (f ? "YES" : "NO") << endl;
  }

  return 0;
}

Submission Info

Judge Result