oj.uz

Submission #493871

# Submission time Handle Problem Language Result Execution time Memory
493871 2021-12-13T09:12:02 Z cadmiumsky Bridges (APIO19_bridges) C++14
29 / 100
 3000 ms 9732 KB 
#include <iostream>
#include <unordered_set>
#include <algorithm>
#include <stack>
#include <vector>
#include <cmath>

using namespace std;
const int mmax = 100005;
const int nmax = 50005;
const int qmax = 100005;
int n, m;
#define x first
#define y second

namespace DSU {
  stack< pair<int,int> >undostack;
  int dsu[nmax];
  int area[nmax];
  void init() {
    for(int i = 0; i < n; i++) {
      dsu[i]=i;
      area[i]=1;
    }
    while(!undostack.empty())
      undostack.pop();
  }
  int father(int x) {
    return (dsu[x]==x ? x : father(dsu[x]));
  }
  void unite(int x , int y) {
    x = father(x);
    y = father(y);
    if(x == y)
      return;
    if(area[x] > area[y]) {
      swap(x, y);
    }
    dsu[y] = x;
    area[x] += area[y];
    undostack.push({x, y});
  }
  int gettime() {
    return undostack.size();
  }
  void popundo() {
    int x, y;
    tie(x,y) = undostack.top();
    undostack.pop();
    dsu[y] = y;
    area[x] -= area[y];
    return;
  }
  void rollback(int x) {
    while(undostack.size() > x)
      popundo();
  }
  int query(int x) {
    return area[father(x)];
  }
};

int weight[mmax];
int prevweight[mmax];
pair<int, int> edge[mmax];

int rez[qmax];

struct query {
  int type, x, w, ind;
  bool operator < (const query& camsus) const {
    return w<camsus.w || (w==camsus.w && type%2>camsus.type%2);
  }
}initq[qmax];

static void solve(int l, int r) {
  DSU::init();
  unordered_set< int > used;
  vector< query > inupd;
  vector< query > qs;
  for(int i = l; i <= r; i++) {
    if(initq[i].type == 1) {
      used.insert(initq[i].x);
      inupd.push_back(initq[i]);
    }
    else {
      qs.push_back(initq[i]);
    } 
  }
  for(int i = 0; i < m; i++) {
    if(used.count(i)==0) {
      qs.push_back(query{3, i, weight[i], 0});
    }
  }
  sort(qs.begin(), qs.end());
  for(auto x:qs) {
    if(x.type == 3) {
      DSU::unite(edge[x.x].x, edge[x.x].y);
      //cout << '+' << edge[x.x].x+1 <<' '<< edge[x.x].y+1 <<' '<< weight[x.x]<< '\n';
    }
    else {
      //cout <<'?'<< x.x+1 << ' '<< x.w <<'\n';
      for(auto upd : inupd) {
        if(upd.ind > x.ind)
          break;
        //cout << "!" << upd.ind <<' '<<upd.type <<' '<<upd.x <<' '<<upd.w <<'\n';
        prevweight[upd.x] = upd.w;
      }
      int inittime=DSU::gettime();
      for(auto e : used) {
        if(prevweight[e]<=x.w) {
          //cout << "+-" << 1+edge[e].x <<' '<< 1+edge[e].y << '\n';
          DSU::unite(edge[e].x, edge[e].y);
        }
        prevweight[e]=weight[e];
      }
      rez[x.ind] = DSU::query(x.x);
      DSU::rollback(inittime);
    }
  }
  //cout << '\n';
}
static void fix(int l, int r) {
  for(int i = l; i <= r; i++) {
    if(initq[i].type==1)
      prevweight[initq[i].x] = weight[initq[i].x] = initq[i].w;
  }
  return;
}

int main() {
  int q;
  cin >> n >> m;
  DSU::init();
  for(int i = 0; i < m; i++) {
    cin >> edge[i].x >> edge[i].y >> weight[i];
    --edge[i].x;
    --edge[i].y;
    weight[i] *= -1; // ca imi convine mai mult cu < decat cu > 
    prevweight[i] = weight[i];
    if(edge[i].x > edge[i].y ) {
      swap(edge[i].x, edge[i].y);
    }
  }
  cin >> q;
  for(int i = 0; i < q; i++) {
    cin >> initq[i].type >> initq[i].x >> initq[i].w;
    initq[i].x--;
    initq[i].w *= -1;
    initq[i].ind=i;
  }
  int buck=sqrt(q); // se poate si mai bine
  int l=0,r=buck-1;
  while(l < q) {
    solve(l,r);
    fix(l,r);
    l += buck;
    r=min(q - 1, r + buck);
  }
  for (int i = 0; i < q; i++) {
    if(initq[i].type == 2)
      cout << rez[i] << '\n';
  }
}
/*
5 5
5 3 6
2 4 49
4 1 44
4 3 74
1 2 85
10
2 2 22
2 2 20
1 3 49
====
2 1 77
1 3 44
1 1 6
====
2 3 49
2 4 31
2 2 54
====
2 2 7

*/

Compilation message

bridges.cpp: In function 'void DSU::rollback(int)':
bridges.cpp:55:28: warning: comparison of integer expressions of different signedness: 'std::stack<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   55 |     while(undostack.size() > x)
      |                            ^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 46 ms 716 KB Output is correct
4 Correct 9 ms 644 KB Output is correct
5 Correct 13 ms 588 KB Output is correct
6 Correct 15 ms 644 KB Output is correct
7 Correct 16 ms 564 KB Output is correct
8 Correct 17 ms 588 KB Output is correct
9 Correct 20 ms 568 KB Output is correct
10 Correct 13 ms 588 KB Output is correct
11 Correct 14 ms 592 KB Output is correct
12 Correct 14 ms 604 KB Output is correct
13 Correct 16 ms 648 KB Output is correct
14 Correct 15 ms 672 KB Output is correct
15 Correct 17 ms 592 KB Output is correct
16 Correct 14 ms 516 KB Output is correct
17 Correct 19 ms 508 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 2519 ms 8300 KB Output is correct
2 Correct 2446 ms 8228 KB Output is correct
3 Correct 2399 ms 8172 KB Output is correct
4 Correct 2602 ms 8216 KB Output is correct
5 Correct 2577 ms 8200 KB Output is correct
6 Correct 2662 ms 8164 KB Output is correct
7 Correct 2961 ms 8220 KB Output is correct
8 Correct 2845 ms 8224 KB Output is correct
9 Correct 75 ms 3684 KB Output is correct
10 Correct 1874 ms 7140 KB Output is correct
11 Correct 1771 ms 7076 KB Output is correct
12 Correct 2364 ms 8336 KB Output is correct
13 Correct 2407 ms 8200 KB Output is correct

Subtask #3
0 / 17.0

# Verdict Execution time Memory Grader output
1 Execution timed out 3061 ms 7008 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Execution timed out 3097 ms 9732 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #5
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2519 ms 8300 KB Output is correct
2 Correct 2446 ms 8228 KB Output is correct
3 Correct 2399 ms 8172 KB Output is correct
4 Correct 2602 ms 8216 KB Output is correct
5 Correct 2577 ms 8200 KB Output is correct
6 Correct 2662 ms 8164 KB Output is correct
7 Correct 2961 ms 8220 KB Output is correct
8 Correct 2845 ms 8224 KB Output is correct
9 Correct 75 ms 3684 KB Output is correct
10 Correct 1874 ms 7140 KB Output is correct
11 Correct 1771 ms 7076 KB Output is correct
12 Correct 2364 ms 8336 KB Output is correct
13 Correct 2407 ms 8200 KB Output is correct
14 Execution timed out 3061 ms 7008 KB Time limit exceeded
15 Halted 0 ms 0 KB -

Subtask #6
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 46 ms 716 KB Output is correct
4 Correct 9 ms 644 KB Output is correct
5 Correct 13 ms 588 KB Output is correct
6 Correct 15 ms 644 KB Output is correct
7 Correct 16 ms 564 KB Output is correct
8 Correct 17 ms 588 KB Output is correct
9 Correct 20 ms 568 KB Output is correct
10 Correct 13 ms 588 KB Output is correct
11 Correct 14 ms 592 KB Output is correct
12 Correct 14 ms 604 KB Output is correct
13 Correct 16 ms 648 KB Output is correct
14 Correct 15 ms 672 KB Output is correct
15 Correct 17 ms 592 KB Output is correct
16 Correct 14 ms 516 KB Output is correct
17 Correct 19 ms 508 KB Output is correct
18 Correct 2519 ms 8300 KB Output is correct
19 Correct 2446 ms 8228 KB Output is correct
20 Correct 2399 ms 8172 KB Output is correct
21 Correct 2602 ms 8216 KB Output is correct
22 Correct 2577 ms 8200 KB Output is correct
23 Correct 2662 ms 8164 KB Output is correct
24 Correct 2961 ms 8220 KB Output is correct
25 Correct 2845 ms 8224 KB Output is correct
26 Correct 75 ms 3684 KB Output is correct
27 Correct 1874 ms 7140 KB Output is correct
28 Correct 1771 ms 7076 KB Output is correct
29 Correct 2364 ms 8336 KB Output is correct
30 Correct 2407 ms 8200 KB Output is correct
31 Execution timed out 3061 ms 7008 KB Time limit exceeded
32 Halted 0 ms 0 KB -