Submission #788282

#	Time	Username	Problem	Language	Result	Execution time	Memory
788282		mannshah1211	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	1 ms	300 KiB

supertrees

#include <bits/stdc++.h>
#include "supertrees.h"
using namespace std;



void build(vector<vector<int>> b);

struct DSU {
	vector<int> link, siz;
	DSU (int n) : link(n), siz(n, 1) {
		iota(link.begin(), link.end(), 0ll);
	}
	
	int get(int x) {
		if (link[x] == x) {
			return x;
		}
		return link[x] = get(link[x]);
	}
	
	bool unite(int a, int b) {
	   a = get(a), b = get(b);
	   if (a == b) {
	   	return false;
	   }
	   
	   if (siz[a] < siz[b]) {
	   	swap(a, b);
	   }
	   link[b] = a;
	   siz[a] += siz[b];
	   return true;
	}
	
	bool same(int a, int b) {
		return (get(a) == get(b));
	}
	
};

int construct(vector<vector<int>> p) {
	vector<vector<int>> b(p.size(), vector<int>(p.size()));
	DSU ds(p.size());
	for (int i = 0; i < p.size(); i++) {
		for (int j = i + 1; j < p.size(); j++) {
			if (p[i][j] != 0) {
				ds.unite(i, j);
			}
		}
	}
	
	for (int i = 0; i < p.size(); i++) {
		for (int j = i + 1; j < p.size(); j++) {
			if (p[i][j] == 0 && ds.same(i, j)) {
				return 0;
			} else if (p[i][j] == 1 && !ds.same(i, j)) {
				return 0;
			}
		}
	}
	
	vector<vector<int>> conncomps(p.size());
	for (int i = 0; i < p.size(); i++) {
		conncomps[ds.get(i)].push_back(i);
	}
	
	for (int i = 0; i < conncomps.size(); i++) {
		if (conncomps[i].size() < 2) {
			continue;
		}
		if (conncomps[i].size() == 2) {
			b[conncomps[i][0]][conncomps[i][1]] = 1;
			b[conncomps[i][1]][conncomps[i][0]] = 1;
			continue;
		}
		for (int j = 0; j < conncomps[i].size(); j++) {
			b[conncomps[i][j]][conncomps[i][(j + 1) % conncomps[i].size()]] = 1;
			b[conncomps[i][(j + 1) % conncomps[i].size()]][conncomps[i][j]] = 1;
		}
	}
	
	build(b);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:45:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |  for (int i = 0; i < p.size(); i++) {
      |                  ~~^~~~~~~~~~
supertrees.cpp:46:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |   for (int j = i + 1; j < p.size(); j++) {
      |                       ~~^~~~~~~~~~
supertrees.cpp:53:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |  for (int i = 0; i < p.size(); i++) {
      |                  ~~^~~~~~~~~~
supertrees.cpp:54:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |   for (int j = i + 1; j < p.size(); j++) {
      |                       ~~^~~~~~~~~~
supertrees.cpp:64:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |  for (int i = 0; i < p.size(); i++) {
      |                  ~~^~~~~~~~~~
supertrees.cpp:68:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |  for (int i = 0; i < conncomps.size(); i++) {
      |                  ~~^~~~~~~~~~~~~~~~~~
supertrees.cpp:77:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |   for (int j = 0; j < conncomps[i].size(); j++) {
      |                   ~~^~~~~~~~~~~~~~~~~~~~~

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