Submission #107261

#	Time	Username	Problem	Language	Result	Execution time	Memory
107261		batmend_kh	Friend (IOI14_friend)	C++14	69 / 100	47 ms	4472 KiB

friend

#include "friend.h"
#include<bits/stdc++.h> 
using namespace std;
 
struct edge{
	int bg;
	int en;
	int flow;
	edge (int bg, int en, int flow){
		this -> bg = bg;
		this -> en = en;
		this -> flow = flow;
	}
};
 
int answer = 0;
vector<int> adj[1005];
int dp_get[1005], dp_didnt_get[1005];
int side[1005];
vector<edge> edges;
vector<pair<int, int> > adj1[1005];
pair<int, int> parent[1005];
bool used[1005];
 
void dp (int current, int parent, int confidence[]) {
	dp_get[current] = confidence[current];
	bool leaf = 1;
	for (int x : adj[current]) {
		if (x == parent) continue;
		leaf = 0;
		dp(x, current, confidence);
	}
	if (leaf) return;
	for (int x : adj[current]) {
		if (x == parent) continue;
		dp_get[current] += dp_didnt_get[x];
		dp_didnt_get[current] += max(dp_didnt_get[x], dp_get[x]);
	}
}
 
void make_edge(int bg, int en) {
	edges.push_back(edge(bg, en, 1));
	adj1[bg].push_back(make_pair(en, edges.size() - 1));
	adj1[en].push_back(make_pair(bg, edges.size() - 1));
}
 
int found_path(int nn) {
	queue <int> q;
	memset(used, 0, sizeof used);
	
	q.push(nn);
	parent[nn] = make_pair(-1, -1);
	used[nn] = 1;
 
	while (!q.empty()) {
		int current = q.front();
		q.pop();
		for (pair<int, int> x : adj1[current]) {
			if (used[x.first]) continue; 
			if (edges[x.second].bg == current && edges[x.second].flow == 1) {
				used[x.first] = 1;
				parent[x.first] = make_pair(current, x.second);
				q.push(x.first);
			}
			if (edges[x.second].en == current && edges[x.second].flow == 0) {
				used[x.first] = 1;
				parent[x.first] = make_pair(current, x.second);
				q.push(x.first);
			}
		}
	}
	return used[nn + 1];
}
 
int findSample(int n, int confidence[],int host[],int protocol[]){
	for (int i = 1; i < n; i++) {
			if (protocol[i] == 1 || protocol[i] == 2) {
				for (int x : adj[host[i]]) {
					adj[x].push_back(i);
					adj[i].push_back(x);
				}
			}
			if (protocol[i] == 0 || protocol[i] == 2) {
				adj[i].push_back(host[i]);
				adj[host[i]].push_back(i);
			}
	}	
	if (n <= 10) {
		for (int i = 0; i < (1<<n); i++) {
			vector<int> group;
			bool found_connectedness = 0;
			for (int j = 0; j < n; j++) {
				if (i & (1<<j)) group.push_back(j);
			}
			for (int i : group) {
				for (int j : group) {
					for (int x : adj[i]) if ( x == j) found_connectedness = 1;
				}
			}
			if (found_connectedness == 1) continue;
			int sum = 0;
			for (int x : group) sum += confidence[x];
			answer = max(answer, sum);
		}
		return answer;
	}
	bool all0 = 1, all1 = 1, all2 = 1;
	for (int i = 1; i < n; i++) {
		if (protocol[i] == 0) {
			all1 = 0;
			all2 = 0;
		}
		if (protocol[i] == 1) {
			all0 = 0;
			all2 = 0;
		}
		if (protocol[i] == 2) {
			all0 = 0;
			all1 = 0;
		}
	}
 
	if (all1 == 1) {
		int sum = 0;
		for (int i = 0; i < n; i++) sum += confidence[i];
		return sum;
	}
	if (all2 == 1) {
		int ma = 0;
		for (int i = 0; i < n; i++) ma = max(ma, confidence[i]);
		return ma;
	}
	if (all0 == 1) {
		dp(0, -1, confidence);
		return max(dp_get[0], dp_didnt_get[0]);
	}
 
	side[0] = 0;
	for (int i = 1; i < n; i++)	{
		if (protocol[i] == 0) side[i] = 1 - side[host[i]];
		if (protocol[i] == 1) side[i] = side[host[i]];
	}
	for (int i = 0; i < n; i++) {
		if (side[i] == 1) continue;
		for (int x : adj[i]) make_edge(i, x);
	}
	for (int i = 0; i < n; i++) {
		if (side[i] == 0) make_edge(n, i);
		if (side[i] == 1) make_edge(i, n + 1);
	}
	int maximum_matching = 0;
	while (found_path(n)) {
		maximum_matching++;
		for (int i = n + 1; parent[i].first != -1; i = parent[i].first) {
			edges[parent[i].second].flow ^= 1;
		}
	}
	return (n - maximum_matching);
}

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