zoukankan      html  css  js  c++  java
  • Moving Tables(贪心或Dp POJ1083)

    Moving Tables
    Time Limit: 1000MS   Memory Limit: 10000K
    Total Submissions: 28304   Accepted: 9446

    Description

    The famous ACM (Advanced Computer Maker) Company has rented a floor of a building whose shape is in the following figure.

    The floor has 200 rooms each on the north side and south side along the corridor. Recently the Company made a plan to reform its system. The reform includes moving a lot of tables between rooms. Because the corridor is narrow and all the tables are big, only one table can pass through the corridor. Some plan is needed to make the moving efficient. The manager figured out the following plan: Moving a table from a room to another room can be done within 10 minutes. When moving a table from room i to room j, the part of the corridor between the front of room i and the front of room j is used. So, during each 10 minutes, several moving between two rooms not sharing the same part of the corridor will be done simultaneously. To make it clear the manager illustrated the possible cases and impossible cases of simultaneous moving.

    For each room, at most one table will be either moved in or moved out. Now, the manager seeks out a method to minimize the time to move all the tables. Your job is to write a program to solve the manager's problem.

    Input

    The input consists of T test cases. The number of test cases ) (T is given in the first line of the input file. Each test case begins with a line containing an integer N , 1 <= N <= 200, that represents the number of tables to move.
    Each of the following N lines contains two positive integers s and t, representing that a table is to move from room number s to room number t each room number appears at most once in the N lines). From the 3 + N -rd
    line, the remaining test cases are listed in the same manner as above.

    Output

    The output should contain the minimum time in minutes to complete the moving, one per line.

    Sample Input

    3 
    4 
    10 20 
    30 40 
    50 60 
    70 80 
    2 
    1 3 
    2 200 
    3 
    10 100 
    20 80 
    30 50 
    

    Sample Output

    10
    20
    30

    Source

    Taejon 2001
    开始做的时候用的贪心后来感觉好麻烦,就又写的Dp;
    贪心
    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <cstdlib>
    #include <algorithm>
    
    using namespace std;
    
    typedef struct node
    {
        int L;
        int R;
        bool operator <(const node &a)const
        {
            if(L<a.L||(L==a.L&&R<a.R))
            {
                return true;
            }
            return false;
        }
    } Edge;
    
    Edge a[300];
    
    bool vis[300];
    
    int main()
    {
        int T,n,x,y;
        scanf("%d",&T);
        while(T--)
        {
            scanf("%d",&n);
            for(int i=0; i<n; i++)
            {
                scanf("%d %d",&x,&y);
                if(x>y)
                {
                    swap(x,y);
                }
                if(x&1)
                {
                    a[i].L=(x+1)/2;
                }
                else
                {
                    a[i].L=x/2;
                }
                if(y&1)
                {
                    a[i].R=(y+1)/2;
                }
                else
                {
                    a[i].R=y/2;
                }
    
            }
            sort(a,a+n);
            memset(vis,false,sizeof(vis));
            int sum=0;
            while(1)
            {
                int ans=-1;
                for(int i=0; i<n; i++)
                {
                    if(!vis[i])
                    {
                        if(a[i].L>ans)
                        {
                            ans=a[i].R;
                            vis[i]=true;
                        }
                    }
                }
                if(ans==-1)
                {
                    break;
                }
                else
                {
                    sum++;
                }
            }
            printf("%d
    ",sum*10);
        }
        return 0;
    }
    

    Dp
    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <cstdlib>
    #include <algorithm>
    using namespace std;
    int Dp[201];
    int main()
    {
        int T,n,x,y;
        scanf("%d",&T);
        while(T--)
        {
            scanf("%d",&n);
            memset(Dp,0,sizeof(Dp));
            for(int i=0; i<n; i++)
            {
                scanf("%d %d",&x,&y);
                if(x>y)
                {
                    swap(x,y);
                }
                x=(x+1)/2;
                y=(y+1)/2;
                Dp[x]+=1;
                Dp[y+1]-=1;
            }
            int sum=0;
            for(int i=1;i<201;i++)
            {
                Dp[i]+=Dp[i-1];
                sum=max(sum,Dp[i]);
            }
            printf("%d
    ",sum*10);
        }
        return 0;
    }
    



  • 相关阅读:
    mysql性能优化之索引优化
    提高mysql千万级大数据SQL查询优化30条经验(Mysql索引优化注意)
    MySQL高级-索引优化
    MySQL性能调优——索引详解与索引的优化
    通过force index了解的MySQL查询的性能优化
    Mysql 日期型,索引查询的问题
    mysql按日期分组(group by)查询统计的时候,没有数据补0的解决办法。
    SQL中Group By的使用
    GROUP BY 与聚合函数 使用注意点
    MYSQL GROUP BY Optimization
  • 原文地址:https://www.cnblogs.com/juechen/p/5255930.html
Copyright © 2011-2022 走看看