Submission #503019

#	Time	Username	Problem	Language	Result	Execution time	Memory
503019		MilosMilutinovic	Friend (IOI14_friend)	C++14	100 / 100	40 ms	7012 KiB

friend

#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
mt19937 mrand(random_device{}()); 
const ll mod=1000000007;
int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
// head

const int N=101000;
int n,a[N],dp[N][2];
vector<PII> e[N];

void dfs(int u) {
	dp[u][0]=a[u];
	for (auto p:e[u]) {
		int v=p.fi,t=p.se;
		dfs(v);
		if(t==0) {
			dp[u][0]=dp[u][0]+dp[v][1];
			dp[u][1]=max(dp[u][1]+dp[v][1],dp[u][1]+dp[v][0]);
		} else if (t==1) {
			dp[u][0]=max({dp[u][0]+dp[v][1],dp[v][0]+dp[u][1],dp[u][0]+dp[v][0]});
			dp[u][1]=dp[u][1]+dp[v][1];
		} else {
			dp[u][0]=max(dp[u][0]+dp[v][1],dp[v][0]+dp[u][1]);
			dp[u][1]=dp[u][1]+dp[v][1];
		}
	}
}

int findSample(int n,int c[],int p[],int t[]) {
	rep(i,0,n) a[i]=c[i];
	per(i,1,n) e[p[i]].pb(mp(i,t[i]));
	dfs(0);
	return max(dp[0][0],dp[0][1]);
}

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