Submission #839079

#	Time	Username	Problem	Language	Result	Execution time	Memory
839079		mohammad_kilani	Toy Train (IOI17_train)	C++17	100 / 100	337 ms	1704 KiB

train

#include "train.h"
#include <bits/stdc++.h>
using namespace std;

const int N = 5010;

int n;

vector< int > ans , g[N] , g2[N] , r , a;

void make(){
	ans = vector< int > (n , -1);
	vector< int > out(n , 0);
	queue < int > q;
	for(int i = 0 ;i < n;i++){
		out[i] = (int)g[i].size();
		if(r[i]){
			out[i] = 0;
			ans[i] = 1;
			q.push(i);
		}
	}
	int node;
	while(!q.empty()){
		node = q.front();
		q.pop();
		for(int pre , i = 0 ;i < (int)g2[node].size();i++){
			pre = g2[node][i];
			if(out[pre] == 0) continue;
			out[pre]--;
			if(a[pre]){
				out[pre] = 0;
				ans[pre] = 1;
				q.push(pre);
				continue;
			}
			if(out[pre] == 0){
				ans[pre] = 1;
				q.push(pre);
			}
		}
	}
	for(int i = 0 ;i < n;i++){
		if(ans[i] == -1)
			ans[i] = 0;
	}
}

std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {
	n = (int)a.size();
	ans.resize(n , -1);
	::r = r;
	::a = a;
	for(int i = 0 ;i < (int)u.size();i++){
		g[u[i]].push_back(v[i]);
		g2[v[i]].push_back(u[i]);
	}
	bool found = true , good;
	while(found){
		make();
		found = false;
		for(int i = 0 ;i < n;i++){
			if(!::r[i]) continue;
			good = false;
			for(int j = 0 ;j < (int)g[i].size();j++){
				if(ans[g[i][j]] == a[i]){
					good = true;
					break;
				}
			}
			if(good){
				if(!a[i]) found = true, ::r[i] = false;
			}
			else{
				if(a[i]) found = true, ::r[i] = false;
			}
		}
	}
	return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 12 / 12
• Subtask 6: 51 / 51