Submission #478382

#	Time	Username	Problem	Language	Result	Execution time	Memory
478382		ponytail	Connecting Supertrees (IOI20_supertrees)	C++17	40 / 100	230 ms	22144 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>
#include <vector>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <string>
 
using namespace std;
 
int dsu[1000];
 
int set_of(int u) {
    if(dsu[u] == u) return u;
    return dsu[u] = set_of(dsu[u]);
}
 
void union_(int u, int v) {
    dsu[set_of(u)] = set_of(v);
}
 
int construct(std::vector<std::vector<int>> p) {
	int n = p.size();
	std::vector<std::vector<int>> answer;
	for (int i = 0; i < n; i++) {
		std::vector<int> row;
		row.resize(n);
		answer.push_back(row);
	}
    for(int i=0; i<n; i++) {
        dsu[i] = i;
    }
    bool st = 0;
    for(int i=0; i<n; i++) {
      for(int j=0; j<n; j++) {
        if(i != j && p[i][j] == 1) st = 1;
      }
    }
  if(!st) {
    vector<vector<int> > v(n);
    for(int i=0; i<n; i++) {
        for(int j=0; j<n; j++) {
            if(p[i][j] > 0) {
                if(set_of(i) != set_of(j)) {
                    union_(i, j);
                }
            }
        }
    }
    for(int i=0; i<n; i++) {
        v[set_of(i)].push_back(i);
    }
    for(int i=0; i<n; i++) {
        if(v[i].size() == 2) {
            if(p[v[i][0]][v[i][1]] == 2) return 0;
            answer[v[i][0]][v[i][1]] = answer[v[i][1]][v[i][0]] = 1;
        }
    }
    for(int i=0; i<n; i++) {
        if(v[i].size() > 2) {
            for(int j=0; j<v[i].size(); j++) {
                answer[v[i][j]][v[i][(j+1) % v[i].size()]] = 1;
                answer[v[i][(j+1) % v[i].size()]][v[i][j]] = 1;
            }
        }
    }
    for(int i=0; i<n; i++) {
        for(int j=0; j<n; j++) {
            if(set_of(i) == set_of(j) && p[i][j] == 0) return 0;
        }
    }
  }
  else {
    for(int i=0; i<n; i++) {
        for(int j=0; j<n; j++) {
            if(p[i][j] == 1 && set_of(i) != set_of(j)) {
                union_(i, j);
                answer[i][j] = answer[j][i] = 1;
            }
        }
    }
    for(int i=0; i<n; i++) {
        for(int j=0; j<n; j++) {
            if(p[i][j] == 0 && set_of(i) == set_of(j)) {
                return 0;
            }
        }
    }
  }
	build(answer);
	return 1;
}
 

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:61:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |             for(int j=0; j<v[i].size(); j++) {
      |                          ~^~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 0 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4