Submission #1291633

#	Time	Username	Problem	Language	Result	Execution time	Memory
1291633		lucaskojima	Connecting Supertrees (IOI20_supertrees)	C++17	19 / 100	182 ms	22196 KiB

supertrees

#include "bits/stdc++.h"
#include "supertrees.h"
#define sz(x) (int)size(x)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)

using namespace std;
using ll = long long;
using pii = pair<int, int>;

const char nl = '\n';
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3f;

struct dsu {
	vector<int> e;
	dsu(int n) : e(n, -1) {}

	int find(int v) { return e[v] < 0 ? v : e[v] = find(e[v]); }
	bool same(int a, int b) { return find(a) == find(b); }
	void une(int a, int b) {
		a = find(a), b = find(b);
		if (a == b) return;
		if (e[a] < e[b]) swap(a, b);
		e[b] += e[a];
		e[a] = b;
	}
};

int construct(vector<vector<int>> p) {
	int n = sz(p);

	dsu dsu(n);
	for (int i = 0; i < n; i++)
		for (int j = i; j < n; j++)
			if (p[i][j] == 2)
				dsu.une(i, j);

	for (int i = 0; i < n; i++)
		for (int j = i; j < n; j++)
			if (p[i][j] == 0 && dsu.same(i, j))
				return 0;

	vector<vector<int>> comp(n);
	for (int i = 0; i < n; i++) {
		int p = dsu.find(i);
		comp[p].push_back(i);
	}

	vector ans(n, vector<int>(n));
	for (int i = 0; i < n; i++) {
		if (sz(comp[i]) <= 1) continue;
		if (sz(comp[i]) == 2) return 0;

		for (int j = 0; j < sz(comp[i]); j++) {
			int a = comp[i][j];
			int b = comp[i][(j + 1) % (sz(comp[i]))];
			ans[a][b] = 1;
			ans[b][a] = 1;
		}
	}

	build(ans);
	return 1;
}

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