Submission #363247

#	Time	Username	Problem	Language	Result	Execution time	Memory
363247		vm152	Traffic (IOI10_traffic)	C++17	50 / 100	671 ms	248172 KiB

traffic

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

#define ios ios_base::sync_with_stdio(0); cin.tie(0) ; cout.tie(0)
#define eb emplace_back
#define mp make_pair
#define f first
#define s second
#define endl '\n'

typedef long long int ll ;

const int MAX = 1e6 ;
vector<int> tree[MAX + 5] ;
vector<int> cnt[MAX + 5] ;
ll sum = 0 ;

ll dfs(int node, int s, int p[]) {
	ll count = 0 ;
 	for (int i : tree[node]) {
 		if (i != s) {
		 	count = dfs(i, node, p) + p[i] ;
		 	cnt[node].eb(count) ;
 		}
 	}
 	ll sm = 0 ;
 	for (int i : cnt[node]) sm += i ;
 	cnt[node].eb(sum - sm - p[node]) ;
 	return count ;
}

int LocateCentre(int n, int p[], int s[], int d[]) {
 	sum = 0 ;
 	for (int i = 0 ; i < n ; i++) {
	 	sum += p[i] ; 
	 	tree[i].clear() ;
	 	cnt[i].clear() ;
	}
 	for (int i = 0; i < n - 1 ; i++) {
	 	tree[s[i]].eb(d[i]) ;
	 	tree[d[i]].eb(s[i]) ;
 	}
 	ll rand = dfs(0, -1, p) ;
 	int index = 0 ;
 	while (cnt[index].empty()) index++ ;
 	sort(cnt[index].begin(), cnt[index].end()) ;
 	reverse(cnt[index].begin(), cnt[index].end()) ;
 	int start = index + 1 ;
 	for (int i = start ; i < n ; i++) {
		 if (!cnt[i].empty()) {
		 	 sort(cnt[i].begin(), cnt[i].end()) ;
		 	 reverse(cnt[i].begin(), cnt[i].end()) ;
			 if (cnt[i][0] < cnt[index][0]) {
			 	 index = i ;
			 }
			 else if (cnt[i][0] == cnt[index][0]) {
			 	 int j = 1, k = 1 ;
			 	 while (j < int(cnt[i].size()) && k < int(cnt[index].size()) && cnt[i][j] == cnt[index][k]) j++, k++ ;
			 	 if (j >= int(cnt[i].size())) index = i ;
			 	 else if (k < int(cnt[index].size()) && cnt[i][j] < cnt[index][k]) index = i ;
			 }
	     }
 	}
 	return index ;
}

/*
int main(){
	 ios ;
	 int n ;
	 cin >> n ;
	 int p[n] ;
	 int s[n] ;
	 int d[n] ;
	 for (int i = 0 ; i < n ; i++)
	 	 cin >> p[i] ;
	 for (int i = 0 ; i < n - 1 ; i++)
	 	 cin >> s[i] ;
	 for (int i = 0 ; i < n - 1 ; i++)
	 	 cin >> d[i] ;
	 int ans = LocateCentre(n, p, s, d) ;
	 cout << ans << endl ;
}
*/

Compilation message (stderr)

traffic.cpp: In function 'int LocateCentre(int, int*, int*, int*)':
traffic.cpp:43:6: warning: unused variable 'rand' [-Wunused-variable]
   43 |   ll rand = dfs(0, -1, p) ;
      |      ^~~~

• Subtask 1: 25 / 25
• Subtask 2: 25 / 25
• Subtask 3: 0 / 25
• Subtask 4: 0 / 25