Submission #569736

#	Time	Username	Problem	Language	Result	Execution time	Memory
569736		ngpin04	Connecting Supertrees (IOI20_supertrees)	C++17	40 / 100	255 ms	31932 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define TASK ""
#define bit(x) (1LL << (x))
#define getbit(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end() 
using namespace std;
template <typename T1, typename T2> bool mini(T1 &a, T2 b) {
	if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maxi(T1 &a, T2 b) {
	if (a < b) {a = b; return true;} return false;
}
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l, int r) {
	return l + rd() % (r - l + 1);
}
const int N = 1e3 + 5;
const int oo = 1e9;
const long long ooo = 1e18;
const int mod = 1e9 + 7; // 998244353;
const long double pi = acos(-1);

vector <int> s[N];

int ans[N][N];
int a[N][N];
int c[N];
int n,comp;

bool vis[N];

int solve() {
	for (int i = 0; i < n; i++) if (!vis[i]) {
		queue <int> q({i});
		vis[i] = true;
		while (q.size()) {
			int u = q.front(); q.pop();
			s[comp].push_back(u);
			c[u] = comp;
			for (int v = 0; v < n; v++) if (a[u][v] > 0) {
				if (!vis[v]) {
					q.push(v);
					vis[v] = true;
				}
			}
		}
		comp++;
	}

	for (int i = 0; i < comp; i++) {
		for (int j : s[i]) 
		for (int k = 0; k < n; k++) {
			if (c[j] == c[k] && a[j][k] == 0)
				return 0;
			if (c[j] != c[k] && a[j][k] > 0)
				return 0;
		}

		vector <int> tree, cir;

		int r = s[i][0];

		for (int j : s[i])
		for (int k : s[i]) 
			if (j != k && a[j][k] == 1)
				r = j;

		for (int j : s[i])
			if (a[r][j] == 1)
				tree.push_back(j);

		for (int j : tree)
		for (int k : tree)
			if (a[j][k] != 1)
				return 0;

		for (int i = 0; i + 1 < (int) tree.size(); i++) {
			int u = tree[i];
			int v = tree[i + 1];
			ans[u][v] = ans[v][u] = 1;
		}

		int cur = 0;
		for (int j : s[i]) if (a[r][j] != 1) {
			if (cur > 0 && a[r][j] != cur)
				return 0;
			cur = a[r][j];
			cir.push_back(j);
		}

		for (int j : cir) 
		for (int k : s[i])
			if (j != k && a[j][k] != cur)
				return 0;
			
		cir.push_back(r);
		if (cir.size() == 2)
			return 0;

		if (cir.size() == 1)
			continue;

		for (int i = 0; i < (int) cir.size(); i++) {
			int u = cir[i];
			int v = cir[(i + 1) % cir.size()];
			ans[u][v] = true;
			ans[v][u] = true;
		}

		if (cur == 3) {
			if (cir.size() == 3)
				return 0;

			int u = cir[0];
			int v = cir[2];
			ans[u][v] = ans[v][u] = 1;
		}
	}

	return 1;
}

int construct(vector<vector<int>> p) {
	n = p.size();
	for (int i = 0; i < n; i++)
	for (int j = 0; j < n; j++)
		a[i][j] = p[i][j];

	int res = solve();

	if (!res)
		return 0;
	vector<vector<int>> answer;
	for (int i = 0; i < n; i++) {
		vector<int> row;
		for (int j = 0; j < n; j++)
			row.push_back(ans[i][j]);
		answer.push_back(row);
	}
	build(answer);
	return res;
}

//#include "grader.cpp"

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