Submission #857162

#	Time	Username	Problem	Language	Result	Execution time	Memory
857162		ntkphong	Friend (IOI14_friend)	C++14	23 / 100	2 ms	604 KiB

friend

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

const int MAXSIZE = 1e5 + 10;
vector<vector<int>> g;

vector<int> vis, col;
vector<int> match;

void dfs(int u, vector<int> &L, vector<int> &R) {
    vis[u] = 1;
    if(!col[u]) L.push_back(u); 
           else R.push_back(u);
    
    for(int v : g[u]) {
        if(vis[v]) continue ;
        col[v] = col[u] ^ 1;
        dfs(v, L, R);
    }
}

int DFS(int u) {
    if(vis[u]) return 0;
    vis[u] = 1;
    
    for(int v : g[u]) {
        if(match[v] == -1 || DFS(match[v])) {
            match[v] = u;
            return 1;
        }
    }
    
    return 0;
}

int sub(int n) {  
    vis.resize(n);
    col.resize(n);
    match.resize(n);
    
    for(int i = 0; i < n; i ++) {
        vis[i] = 0;
        col[i] = 0;
    }
    
    int total = 0;
    for(int i = 0; i < n; i ++) {
        if(vis[i]) continue ;
        
        vector<int> L, R;
        dfs(i, L, R);
        
        for(int x : R) match[x] = -1;
        
        for(int x : L) {
            for(int y : L) {
                vis[y] = 0;
            }
            
            DFS(x);
        }
        
        for(int x : R) total += match[x] != -1;
    }
    
    return n - total;
}

int findSample(int n, int confidence[], int host[], int protocol[]){
    g.resize(n);
    
    for(int i = 1; i < n; i ++) {
        int p = host[i];
        
        if(protocol[i] == 0 || protocol[i] == 2) {
            g[i].push_back(p);
            g[p].push_back(i);
        }
        
        if(protocol[i] == 1 || protocol[i] == 2) {
            for(int v : g[p]) {
                g[i].push_back(v);
                g[v].push_back(i);
            }
        }
    }
    
    return sub(n);
}

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