Submission #808942

#	Time	Username	Problem	Language	Result	Execution time	Memory
808942		OrazB	Friend (IOI14_friend)	C++14	8 / 100	6 ms	6740 KiB

friend

#include <bits/stdc++.h>
// #include "friend.h"
using namespace std;
#define all(x) (x).begin(), (x).end()
#define ll long long int
#define pii pair <int, int>
#define pb push_back
#define ff first
#define ss second

const int N = 1e5+5;
int c[N], dp[N][2];
ll mx = 0;
vector<int> E[N];

void bit(int x, int n, int A[]){
	if (x == n){
		ll sum = 0;
		for (int i = 0; i < n; i++){
			if (c[i]){
				for (auto j : E[i]) if (c[j]) return;
				sum += A[i];
			}
		}
		mx = max(mx, sum);
		return;
	}
	for (int i = 0; i < 2; i++){
		c[x] = i;
		bit(x+1, n, A);
	}
}
void dfs(int nd, int pr, int A[]){
	int a = 0;
	for (auto i : E[nd]){
		if (i == pr) continue;
		dfs(i, nd, A);
		a += dp[i][0];
		dp[nd][0] += max(dp[i][1], dp[i][0]);
	}
	dp[nd][1] = a+A[nd];
}

int findSample(int n, int A[], int u[], int v[]){
	int sub0 = 0, sub1 = 0, sub2 = 0;
	int sum = 0;
	for (int i = 0; i < n; i++) sum += A[i];
	dp[0][1] = A[1];
	for (int i = 1; i < n; i++){
		if (v[i] == 2) sub2 = 1;
		if (v[i] == 0) sub0 = 1;
		if (v[i] == 1) sub1 = 1;
 		
 		if (v[i] == 1 or v[i] == 2){
			int a = 0;
			for (auto j : E[u[i]]){
				E[i].pb(j);
				E[j].pb(i);
				dp[i][0] += max(dp[j][0], dp[j][1]);
				a += dp[j][0];
			}
			dp[i][1] = a+A[i];
		}
		if (v[i] == 0 or v[i] == 2){
			E[i].pb(u[i]);
			E[u[i]].pb(i);
			dp[i][0] = max(dp[u[i]][0], dp[u[i]][1]);
			dp[i][1] = dp[u[i]][0]+A[i];
		}
	}
	if (!sub2) return max(dp[n-1][1], dp[n-1][0]);
	if (!sub0 and !sub2) return sum;
	if (!sub0 and !sub1) return *max_element(A, A+n);
	if (!sub1 and !sub2){
		dfs(0, -1, A);
		return max(dp[0][1], dp[0][0]);
	}
	bit(0, n, A);
	return mx;
}


// int main ()
// {
// 	ios::sync_with_stdio(false);
// 	cin.tie(0);
// 	int n;
// 	cin >> n;
// 	int A[n], a[n], b[n];
// 	for (int i = 0; i < n; i++) cin >> A[i];
// 	for (int i = 1; i < n; i++) cin >> a[i] >> b[i];
// 	cout << findSample(n, A, a, b);
// }	

• Subtask 1: 0 / 11
• Subtask 2: 0 / 8
• Subtask 3: 8 / 8
• Subtask 4: 0 / 19
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31