Submission #314555

#	Time	Username	Problem	Language	Result	Execution time	Memory
314555		kostia244	Connecting Supertrees (IOI20_supertrees)	C++17	100 / 100	266 ms	22520 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>
using namespace std;
const int maxn = 1<<12;
int n;
vector<vector<int>> res;
struct dsu {
	vector<int> c[maxn];
	int p[maxn];
	dsu(int n = 0) {
		for(int i = 0; i < n; i++) {
			p[i] = i;
			c[i].push_back(i);
		}
	}
	int par(int a) {
		if(p[a] == a) return a;
		return a = par(p[a]);
	}
	void unite(int i, int j) {
		i = par(i), j = par(j);
		if(i == j) return;
		if(c[i].size() < c[j].size()) swap(i, j);
		for(auto x : c[j]) c[i].push_back(x);
		p[j] = i;
	}
};
int construct(std::vector<std::vector<int>> p) {
	for(auto i : p) for(auto j : i) if(j == 3) return 0;
	n = p.size();
	res.resize(n, vector<int>(n, 0));
	dsu c1(n), c2(n);
	for(int i = 0; i < n; i++)
		for(int j = 0; j < n; j++)
			if(p[i][j] == 1) c1.unite(i, j);
	for(int i = 0; i< n; i++)
		for(int j = 0; j < n; j++) {
			int x = c1.par(i), y = c1.par(j);
			if(p[i][j] != p[x][y]) return 0;
		}
	for(int i = 0; i < n; i++) if(c1.par(i) == i)
		for(int j = 0; j < n; j++) if(c1.par(j) == j) {
			if(p[i][j] == 2) {
				c2.unite(i, j);
			}
		}
	for(int i = 0; i < n; i++) {
		if(c1.par(i) == i) {
			int lst = -1;
			for(auto x : c1.c[i]) {
				if(lst != -1) res[lst][x] = 1;
				lst = x;
			}
		}
		if(c2.par(i) == i) {
			if(c2.c[i].size() == 1) continue;
			if(c2.c[i].size() == 2) return 0;
			for(auto x : c2.c[i])
			for(auto y : c2.c[i])
			if(p[x][y] != 2 && x != y) return 0;
			int lst = -1;
			c2.c[i].push_back(c2.c[i][0]);
			for(auto x : c2.c[i]) {
				if(lst != -1) res[lst][x] = 1;
				lst = x;
			}
		}
	}
	for(int i = 0; i < n; i++)
		for(int j = 0; j < n; j++) if(res[i][j] == 1) res[j][i] = 1;
	build(res);
	return 1;
}

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