Submission #632254

#	Time	Username	Problem	Language	Result	Execution time	Memory
632254		device	Traffic (IOI10_traffic)	C++17	100 / 100	1136 ms	170664 KiB

traffic

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll a[1000000], ans, mn = INT_MAX;
vector<int> adj[1000000];
void init(int cur, int par = -1){
	for(int nxt:adj[cur]){
		if(nxt == par) continue;
		init(nxt, cur);
		a[cur] += a[nxt];
	}
}
void dfs(int cur, ll val = 0, int par = -1){
	ll mx = val;
	for(int nxt:adj[cur]){
		if(nxt == par) continue;
		mx = max(mx, a[nxt]);
		dfs(nxt, val + a[cur] - a[nxt], cur);
	}
	if(mx < mn){
		mn = mx;
		ans = cur;
	}
}
int LocateCentre(int n, int p[], int s[], int d[]){
	for(int i = 0; i < n; i++) a[i] = p[i];
	for(int i = 0; i < n-1; i++){
		adj[s[i]].push_back(d[i]);
		adj[d[i]].push_back(s[i]);
	}
	init(0); dfs(0);
	return ans;
}

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