zoukankan      html  css  js  c++  java
  • HDU2647-Reward(拓扑排序)

    Reward

    Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
    Total Submission(s): 3854    Accepted Submission(s): 1177


    Problem Description
    Dandelion's uncle is a boss of a factory. As the spring festival is coming , he wants to distribute rewards to his workers. Now he has a trouble about how to distribute the rewards.
    The workers will compare their rewards ,and some one may have demands of the distributing of rewards ,just like a's reward should more than b's.Dandelion's unclue wants to fulfill all the demands, of course ,he wants to use the least money.Every work's reward will be at least 888 , because it's a lucky number.
     

    Input
    One line with two integers n and m ,stands for the number of works and the number of demands .(n<=10000,m<=20000)
    then m lines ,each line contains two integers a and b ,stands for a's reward should be more than b's.
     

    Output
    For every case ,print the least money dandelion 's uncle needs to distribute .If it's impossible to fulfill all the works' demands ,print -1.
     

    Sample Input
    2 1 1 2 2 2 1 2 2 1
     

    Sample Output
    1777 -1
     
    题意: 有n个人。m个关系:输入a,b 表示a比b大。

    最少的工资为888,让你求最小的工资和


    思路:拓扑排序。依据层数计算每一个人的工资,累加就可以。
    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <vector>
    #include <string>
    #include <algorithm>
    #include <queue>
    using namespace std;
    
    const int maxn = 10000+10;
    vector<int> g[maxn];
    int du[maxn];
    int n,m;
    int sum;
    queue<int> que;
    int head[maxn];
    int now;
    void init(){
        sum = 0;
        now = 888;
        memset(du,0,sizeof du);
        for(int i = 0; i <= n; i++) g[i].clear();
        while(!que.empty()) que.pop();
    }
    
    int main(){
    
        while(~scanf("%d%d",&n,&m)){
            init();
            int a,b;
            while(m--){
                scanf("%d%d",&a,&b);
                g[b].push_back(a);
                du[a]++;
            }
            int cnt = 0;
            for(int i = 1; i <= n; i++){
                if(du[i]==0){
                    que.push(i);
                    cnt++;
                }
            }
            while(!que.empty()){
                int qsize = que.size();
                while(qsize--){
                    int k = que.front();
                    sum+=now;
                    que.pop();
                    for(int i = 0; i < g[k].size(); i++){
                        int x = g[k][i];
                        du[x]--;
                        if(du[x]==0){
                            que.push(x);
                            cnt++;
                        }
                    }
                }
                now++;
    
            }
            if(cnt<n){
                printf("-1
    ");
            }else{
                printf("%d
    ",sum);
            }
        }
        return 0;
    }
    


  • 相关阅读:
    10分钟学会Python
    Python接口自动化(二)接口开发
    Python接口自动化(一)接口基础
    去掉webstorm内容区域右侧的一条竖线
    webstorm识别element-ui的标签
    vue中点击复制粘贴功能 clipboard 移动端
    vue pc element-ui class
    禁止浏览器记住密码
    js 将网络图片格式转为base64 canvas 跨域
    移动端网页在本地服务器调试
  • 原文地址:https://www.cnblogs.com/mfrbuaa/p/5048279.html
Copyright © 2011-2022 走看看