Submission #813029

#	Time	Username	Problem	Language	Result	Execution time	Memory
813029		KemalK	Connecting Supertrees (IOI20_supertrees)	C++17	0 / 100	1 ms	340 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include <bits/stdc++.h>
using namespace std;
// DSU
int Root(int a, vector <int> &root){
	if (root[a] == a){
		return a;
	}
	return (root[a] = Root(root[a], root));
}
void unit(int a, int b, vector <int> &root, vector <int> &sz){
	a = Root(a, root);
	b = Root(b, root);
	if (a != b){
		if (sz[a] < sz[b]){
			swap(a, b);
		}
		root[b] = root[a];
		sz[a] += sz[b];
	}
}
int construct(std::vector<std::vector<int>> p) {
	int n = p.size();
	vector<vector <int>> answer(n, vector <int> (n));
	vector <int> root(n), sz(n, 1);
	for (int i = 0; i < n; i++){
		root[i] = i;
	}
	int check = 0;
	for (int i = 0; i < n; i++){
		for (int j = 0; j < n; j++){
			if (p[i][j] != 1){
				check = max(check, p[i][j]);
			}
		}
	}
	if (check != 2 and check != 3){
		for (int i = 0 ; i < n; i++){
			for (int j = 0; j < n; j++){
				if(p[i][j]){
					unit(i, j, root, sz);
				}
			}
		}
		for (int i = 0; i <= n; i++){
			for (int j = 0; j < n; j++){
				if (p[i][j] == 1 and Root(i, root) != Root(j, root)){
					return 0;
				}
			}
		}
		vector <vector <int>> forest(n, vector <int> (n));
		for (int i = 0; i < n; i++){
			vector <int> branch;
			for (int j = 0; j < n; j++){
				if (Root(j, root) == i){
					branch.push_back(j);
				}
			}
			for (int j = 0; j + 1 < branch.size(); j++){
				answer[branch[j]][branch[j + 1]] = 1;
				answer[branch[j + 1]][branch[j]] = 1;
			}
		}
	}
	build(answer);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:61:26: 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 + 1 < branch.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