Submission #393187

#	Time	Username	Problem	Language	Result	Execution time	Memory
393187		abdzag	Connecting Supertrees (IOI20_supertrees)	C++17	75 / 100	361 ms	22100 KiB

supertrees

#include<bits/stdc++.h>
#include"supertrees.h"
#define rep(i,a,b) for(int i=a;i<int(b);i++)
#define rrep(i,a,b)for(int i=a;i>int(b);i--)
#define all(v) v.begin(),v.end()
#define trav(a,v) for(auto& a: v)
typedef long long ll;
using namespace std;
const long long inf = 1e15;

vector<ll> p(2001);
vector<ll> Rank(2001);
ll Ufindset(ll i) {
	if (p[i] == i)return i;
	return p[i] = Ufindset(p[i]);
}
void UjoinSet(ll i, ll j) {
	ll si = Ufindset(i);
	ll sj = Ufindset(j);
	if (sj == si)return;
	if (Rank[sj] > Rank[si])swap(sj, si);
	p[sj] = si;
	if (Rank[sj] == Rank[si]) Rank[si]++;
}
void print(vector<ll> v) {
	trav(a, v)cout << a << " ";
	cout << endl;
}
int construct(vector<vector<int>> v) {
	rep(i, 0, 2001)p[i] = i;
	vector<vector<int>> b(v.size(), vector<int>(v.size()));
	rep(i, 0, v.size()) {
		ll root = p[i];
		ll last = i;
		ll two = 0;
		rep(j, 0, v.size()) {
			if (v[i][j] == 3)return 0;
			if (v[i][j]) {
				if (v[i][j] == 2) {
					p[p[i]] = i;
					p[i] = i;
					two++;
				}
				else if (v[i][j] == 1)UjoinSet(i, j);
			}
		}
	}

	rep(i, 0, v.size()) Ufindset(i);
	rep(i, 0, v.size()) {
		ll last = i;
		rep(j, 0, v.size()) {
			if (i == j)continue;
			if (v[i][j]) {
				if (v[i][j]==1) {
					if (p[i] == i) {
						UjoinSet(last, j);
						b[last][j] = 1;
						b[j][last] = 1;
					}
					last = j;
				}
			}
		}
	}

	rep(i, 0, v.size()) {
		ll last = i;
		ll two = 0;
		rep(j, 0, v.size()) {
			Ufindset(j);
			if (i == j)continue;
			if (v[i][j]) {
				if (p[j] != j) {
					if (p[j] != p[i]) {
						if (v[p[i]][p[j]] != v[i][j])return 0;
					}
				}
			}
			else if (p[j] == p[i]) return 0;
			if (p[i] == i) {
				if (p[j] == j) {
					if (v[i][j] == 2) {
						two++;
						
						UjoinSet(last, j);
						b[last][j] = 1;
						b[j][last] = 1;
						last = j;
					}
				}
				

			}
		}
		if (p[i]==i&&two) {
			if (two == 1)return 0;
			if (p[i] == i) {
				UjoinSet(last, i);
				b[last][i] = 1;
				b[i][last] = 1;
			}
		}
	}
	build(b);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:33:6: warning: unused variable 'root' [-Wunused-variable]
   33 |   ll root = p[i];
      |      ^~~~
supertrees.cpp:34:6: warning: unused variable 'last' [-Wunused-variable]
   34 |   ll last = i;
      |      ^~~~

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