Submission #145479

#	Time	Username	Problem	Language	Result	Execution time	Memory
145479		TAMREF	Friend (IOI14_friend)	C++11	27 / 100	39 ms	4984 KiB

friend

#include "friend.h"
#include <bits/stdc++.h>
#define all(v) (v).begin(),(v).end()
using namespace std;

int n;
vector<int> c, h, p;

int bf(){
	vector<vector<int>> e(n, vector<int>(n));
	for(int i = 1; i < n; i++){
		switch(p[i]){
			case 0:
			e[h[i]][i] = e[i][h[i]] = 1;
			break;
			case 1:
			for(int j = 0; j < i; j++){
				if(e[h[i]][j]) e[i][j] = e[j][i] = 1;
			}
			break;
			case 2:
			e[h[i]][i] = e[i][h[i]] = 1;
			for(int j = 0; j < i; j++){
				if(e[h[i]][j]) e[i][j] = e[j][i] = 1;
			}
			break;			
		}
	}
	int ans = 0;
	for(int b = 0; b < (1<<n); b++){
		int lans = 0;
		for(int i = 0; i < n; i++){
			if(~b >> i & 1) continue;
			for(int j = 0; j < n; j++){
				if(~b >> j & 1) continue;
				if(e[i][j]) goto FAIL;
			}
		}
		for(int i = 0; i < n; i++){
			if(b >> i & 1){
				lans += c[i];
			}
		}
		ans = max(ans, lans);
		FAIL:
		continue;
	}
	return ans;
}

vector<int> G[100005];
int dp[100005][2];

void dfs(int x){
	dp[x][1] = c[x];
	for(int u : G[x]){
		dfs(u);
		dp[x][0] += dp[u][1];
		dp[x][1] += dp[u][0];
	}
}
int tree_dp(){
	for(int i = 1; i < n; i++) G[h[i]].push_back(i);
	dfs(0);
	return max(dp[0][0], dp[0][1]);
}

int findSample(int N, int C[], int H[], int P[]){
	n = N; 
	c = vector<int>(C,C+n);
	h = vector<int>(H,H+n);
	p = vector<int>(P,P+n);
	int uq;
	p[0] = p[1];
	if((uq = *min_element(all(p))) == *max_element(all(p))){
		switch(uq){
			case 0:
			return tree_dp();
			case 1:
			return accumulate(all(c), 0);
			case 2:
			return *max_element(all(c));
		}
	}
	if(n <= 10) return bf();
	return 0;
}

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