Submission #982937

#	Time	Username	Problem	Language	Result	Execution time	Memory
982937		tamir1	Connecting Supertrees (IOI20_supertrees)	C++17	40 / 100	190 ms	24148 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include <bits/stdc++.h>
using namespace std;
int sz[1001],par[1001],vis[1001];
int find(int a){
	if(a==par[a]) return a;
	int x=find(par[a]);
	par[a]=x;
	return x;
}
vector<int> v[1001],x,y;
int construct(std::vector<std::vector<int>> p) {
	int n = p.size();
	for(int i=0;i<n;i++){
		sz[i]=1;
		par[i]=i;
		for(int j=0;j<n;j++){
			if(p[i][j]==3) return 0;
		}
	}
	if(n==1){
		build({{0}});
		return 1;
	}
	std::vector<std::vector<int>> answer(n,vector<int> (n,0));
	for (int i = 0; i < n; i++) {
		for(int j=0;j<n;j++){
			int x=find(i);
			int y=find(j);
			if(p[i][j]==0 && x==y) return 0;
			if(p[i][j]!=0){
				if(x==y) continue;
				if(sz[x]<sz[y]) swap(x,y);
				else if(sz[x]==sz[y] && x>y) swap(x,y);
				sz[x]+=sz[y];
				par[y]=x;
			}
		}
	}
	for(int i=0;i<n;i++){
		par[i]=find(i);
		v[par[i]].push_back(i);
	}
	
	for(int i=0;i<n;i++){
		int k=v[i].size();
		if(k==0 || k==1) continue;
		x.clear();
		y.clear();
		memset(vis,0,sizeof vis);
		for(int j=0;j<k;j++){
			bool a=0;
			for(int l=0;l<k;l++){
				if(l==j) continue;
				int e=p[v[i][j]][v[i][l]];
				if(e==1){
					a=1;
					break;
				}
			}
			if(!a){
				if(vis[v[i][j]]==1) return 0;
				vis[v[i][j]]=2;
				continue;
			}
			if(vis[v[i][j]]==2) return 0;
			vis[v[i][j]]=1;
			for(int l=0;l<k;l++){
				if(l==j) continue;
				int e=p[v[i][j]][v[i][l]];
				if(e==1){
					if(vis[v[i][l]]==2) return 0;
					vis[v[i][j]]=1;
				}
				else{
					if(vis[v[i][l]]==1) return 0;
					vis[v[i][j]]=2;
				}
			}
		}
		for(int j=0;j<k;j++){
			if(vis[v[i][j]]==1) x.push_back(v[i][j]);
			else y.push_back(v[i][j]);
		}
		int p=x.size();
		int q=y.size();
		if(q==1 || (q==2 && p<1)) return 0;
		for(int j=0;j<p-1;j++){
			answer[x[j]][x[j+1]]=1;
			answer[x[j+1]][x[j]]=1;
		}
		for(int j=0;j<q-1;j++){
			answer[y[j]][y[j+1]]=1;
			answer[y[j+1]][y[j]]=1;
		}
		if(q!=0){
		if(p==0){
			answer[y[0]][y[q-1]]=1;
			answer[y[q-1]][y[0]]=1;
		}
		else{
			answer[y[0]][x[0]]=1;
			answer[x[0]][y[0]]=1;
			answer[y[q-1]][x[0]]=1;
			answer[x[0]][y[q-1]]=1;
		}}
	}
	build(answer);
	return 1;
}

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