Submission #312175

#	Time	Username	Problem	Language	Result	Execution time	Memory
312175		AmineTrabelsi	Traffic (IOI10_traffic)	C++14	100 / 100	1338 ms	156792 KiB

traffic

#include "bits/stdc++.h"
using namespace std;
using ll = long long;
#define pb push_back 
#define mp make_pair
#define f first
#define s second
#define sz(x) ((int)x.size())
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()

// Hi
const int M = 1e6;
vector<int> gr[M];
int *people;
ll sum[M];
int from[M];
void dfs(int i,int par){
	sum[i] = people[i];
	for(auto u:gr[i]){
		if(u!=par){
			from[u]=i;
			dfs(u,i);
			sum[i]+=sum[u];
		}
	}
}/*
ll df(int i,int par){
	ll res = people[i];
	for(auto u:gr[i]){
		if(u != par){
			res += df(u,i);
		}
	}
	return res;
}*/
ll LocateCentre(int n,int p[],int ff[],int d[]){
	for(int i=0;i<n-1;i++){
		gr[ff[i]].pb(d[i]);
		gr[d[i]].pb(ff[i]);
	}
	people = p;
	dfs(0,0);
	from[0]=-1;
	ll res = 1e18;
	int city = 0;
	for(int i=0;i<n;i++){
		ll x = 0;
		//cout<<i<<"\n";
		for(auto e:gr[i]){
			if(i == from[e]){
				//cout<<e<< " "<<sum[e]<<'\n';
				x = max(x,sum[e]);
			}else //cout<<e<<" "<<sum[0]-sum[i]<<"\n",
				x = max(x,sum[0]-sum[i]);
		}
		if(x < res){
			city = i;
			res = x;
		}
		//cout<<'\n';
	}
	return city;
}
/*
int main(){
	int p[6] = {10,10,10,10,10,10},s[5] = {1,2,3,4,0},d[5] = {5,1,2,1,4}; // 1
	//int p[5] = {10,10,10,10,50},s[4] = {1,2,3,4},d[4] = {0,0,0,0}; // 4
	cout<<LocateCentre(6,p,s,d)<<'\n';
	return 0;
}

*/

• Subtask 1: 25 / 25
• Subtask 2: 25 / 25
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25