Submission #838600

#	Time	Username	Problem	Language	Result	Execution time	Memory
838600		SoulKnight	Connecting Supertrees (IOI20_supertrees)	C++17	0 / 100	1 ms	212 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include <iostream>
#include <algorithm>
#include <map>
#include <numeric>
#include <cstring>

using namespace std;

#define ll long long
#define ln '\n'

const int N = 1000 + 5;

int par[N], rk[N];
map<int, vector<int>> mp;
bool ok = true;


int find(int u){return ((u == par[u])? u: par[u]=find(par[u]));}

void add(int u, int v, int c){
	u = find(u);
	v = find(v);

	// if (rk[u] == -1 && rk[v] == -1){
	// 	rk[u] = rk[v] = c;
	// } else if (rk[u] == -1 && rk[v] == c) rk[u] = c;
	// else if (rk[v] == -1 && rk[u] == c) rk[v] = c;
	// else ok = false;

	if (u != v) par[u] = 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);
	}

	iota(par, par+n, 0);
	memset(rk, -1, sizeof(rk));


	for (int i = 0; i < n; i++){
		for (int j = i+1; j < n; j++){
			if (p[i][j] == 0) continue;
			add(i, j, p[i][j]);
		}
	}

	if (!ok) return 0;
	for (int i = 0; i < n; i++){
		for (int j = i+1; j < n; j++){
			if (!p[i][j] && find(i) == find(j)) return 0;
		}
	}


	for (int i = 0; i < n; i++){
		mp[find(i)].push_back(i);
	}

	for (auto& [p, v]: mp){
		// if (rk[p] == 1){
		// 	for (auto& u: v){
		// 		if (u != p) answer[u][p] = answer[p][u] = 1;
		// 	}
		// } else {
		// 	if (v.size() < 2) return 0;

		// 	for (int i = 1; i < v.size(); i++){
		// 		answer[v[i]][v[i-1]] = answer[v[i-1]][v[i]] = 1;
		// 	}
		// 	answer[v.back()][v.front()] = answer[v.front()][v.back()] = 1;
		// }
		if (v.size() < 2) return 0;
		for (int i = 1; i < v.size(); i++){
			answer[v[i]][v[i-1]] = answer[v[i-1]][v[i]] = 1;
		}
		answer[v.back()][v.front()] = answer[v.front()][v.back()] = 1;
	}


	build(answer);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:83:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |   for (int i = 1; i < v.size(); i++){
      |                   ~~^~~~~~~~~~

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