POJ 2342 Anniversary Party ( 树形DP )

标签：算法   dp   

deque 的插入操作不一定有 vector 快

#include <iostream>
#include <cstring>
#include <fstream>
#include <vector>
using namespace std;

#define NOT_SELECTED 0
#define SELECTED 1
#define SIZE 6001

vector< int > relations[SIZE];
bool visited[SIZE];
int DP[SIZE][2];
int farents[SIZE];


void dfs( int node ){
    
    if( visited[node] )
        return;
        
    visited[node] = true;
    
    for( int i = 0; i < relations[node].size(); ++i ){
        int next = relations[node][i];
        if( !visited[next] ){
            dfs( next );
            DP[node][NOT_SELECTED] += max( DP[next][NOT_SELECTED], DP[next][SELECTED] );
            DP[node][SELECTED]     += DP[next][NOT_SELECTED];
        }
    }
}


int main(){

    int employees_num;
    int supervisor, employee;
    int ans = 0;

    while( cin >> employees_num ){

        memset( visited, false, sizeof( visited ) );
        memset( DP, 0, sizeof( DP ) );
        memset( farents, 0, sizeof( farents ) );

        for ( int i = 1; i <= employees_num; ++i ){
            cin >> DP[i][SELECTED];
            relations[i].clear();
        }

        while( true ){
            cin >> employee >> supervisor;
            if( employee == 0 && supervisor == 0 )
                break;
            farents[employee] = supervisor;
            relations[supervisor].push_back( employee );
        }

        for( int i = 1; i <= employees_num; ++i ){
            if( farents[i] == 0 ){
                dfs( i );
                int new_ans = max( DP[i][NOT_SELECTED], DP[i][SELECTED] );
                ans = max( ans, new_ans );
            }
        }
        
        cout << ans << endl;
        
    }
    
    return 0;
    
}

POJ 2342 Anniversary Party ( 树形DP )

标签：算法   dp   

原文地址：http://blog.csdn.net/pandora_madara/article/details/43878415