zoukankan      html  css  js  c++  java
  • POJ3723 Conscription

    Conscription

    Description

    Windy has a country, and he wants to build an army to protect his country. He has picked up N girls and M boys and wants to collect them to be his soldiers. To collect a soldier without any privilege, he must pay 10000 RMB. There are some relationships between girls and boys and Windy can use these relationships to reduce his cost. If girl x and boy y have a relationship d and one of them has been collected, Windy can collect the other one with 10000-d RMB. Now given all the relationships between girls and boys, your assignment is to find the least amount of money Windy has to pay. Notice that only one relationship can be used when collecting one soldier.

    Input

    The first line of input is the number of test case.
    The first line of each test case contains three integers, N, M and R.
    Then R lines followed, each contains three integers xi, yi and di.
    There is a blank line before each test case.

    1 ≤ N, M ≤ 10000
    0 ≤ R ≤ 50,000
    0 ≤ xi < N
    0 ≤ yi < M
    0 < di < 10000

    Output

    For each test case output the answer in a single line.

    Sample Input

    2
    
    5 5 8
    4 3 6831
    1 3 4583
    0 0 6592
    0 1 3063
    3 3 4975
    1 3 2049
    4 2 2104
    2 2 781
    
    5 5 10
    2 4 9820
    3 2 6236
    3 1 8864
    2 4 8326
    2 0 5156
    2 0 1463
    4 1 2439
    0 4 4373
    3 4 8889
    2 4 3133
    

    Sample Output

    71071
    54223
    

    翻译一下就是n个女孩,m个男孩,全部要招募,但是有些女孩x和男孩y有关系,如果已经招募了其中一个,另一个就只需要10000- d了,求最小花费。
    开始是想最小生成树,求招募m+n个人最小花费,预处理时用10000先减去d,再求最小生成树,但是图可能不是连通图,所以对每个联通子图求最小生成树,再加上树的个数 num*10000,当然,一个人也是一棵树,可就是一直wa。
    但是,如果反过来,求n+m个人能优惠的钱数,最后用总钱数再减去它就行了,也不用预处理。

    #include<iostream>
    #include<algorithm>
    using namespace std;
    
    char buf[100000],*L=buf,*R=buf;
    #define gc() L==R&&(R=(L=buf)+fread(buf,1,100000,stdin),L==R)?EOF:*L++;
    template<typename T>
    inline void read(T&x) {
        char ch=gc();
        x=0;
        while (ch<'0'||ch>'9')
            ch=gc();
        while (ch>='0'&&ch<='9')
            x=(x<<3)+(x<<1)+ch-48,ch=gc();
    }
    
    const int MAXN=5e4+20;
    int fa[MAXN],Rank[MAXN];
    
    inline int find(int x) {
        while(fa[x]!=x)
            x=fa[x]=fa[fa[x]];
        return x;
    }
    inline void merge(int x,int y) {
        int xx=find(x),yy=find(y);
        if(xx==yy)return;
    
        if(Rank[xx]<Rank[yy])fa[xx]=yy;
    
        else {
            fa[yy]=xx;
            if(Rank[xx]==Rank[yy])++Rank[xx];
        }
    }
    inline void init() {
        for(int i=0; i<MAXN; ++i){
            fa[i]=i,Rank[i]=0;
        }
    }
    struct Node {
        int x,y,v;
        bool operator<(const Node&b)const {
            return v>b.v;
        }
    } p[MAXN];
    int main() {
        freopen("in.txt","r",stdin);
        int t;
        read(t);
        while(t--) {
            int n,m,r;
            read(n),read(m),read(r);
            init();
            for(int i=0; i<r; ++i) {
                read(p[i].x),read(p[i].y),read(p[i].v);
                p[i].y+=n;//女生: [0,n-1],男生: [n,m+n];
            }
            int ans=0;//优惠多少钱
            sort(p,p+r);
            for(int i=0; i<r; ++i) {
                if(find(p[i].x)==find(p[i].y))
                    continue;
                merge(p[i].x,p[i].y);
                ans+=p[i].v;
                //加个边数判断也行
            }
            printf("%d
    ",(m+n)*10000-ans);//总钱数减去优惠的钱数
        }
        return 0;
    }
    
    //正着算,居然过了
    #include<iostream>
    #include<algorithm>
    using namespace std;
    
    char buf[100000],*L=buf,*R=buf;
    #define gc() L==R&&(R=(L=buf)+fread(buf,1,100000,stdin),L==R)?EOF:*L++;
    template<typename T>
    inline void read(T&x) {
        char ch=gc();
        x=0;
        while (ch<'0'||ch>'9')
            ch=gc();
        while (ch>='0'&&ch<='9')
            x=(x<<3)+(x<<1)+ch-48,ch=gc();
    }
    
    const int MAXN=5e4+20;
    int fa[MAXN],Rank[MAXN];
    
    inline int find(int x) {
        while(fa[x]!=x)
            x=fa[x]=fa[fa[x]];
        return x;
    }
    inline void merge(int x,int y) {
        int xx=find(x),yy=find(y);
        if(xx==yy)return;
    
        if(Rank[xx]<Rank[yy])fa[xx]=yy;
    
        else {
            fa[yy]=xx;
            if(Rank[xx]==Rank[yy])++Rank[xx];
        }
    }
    inline void init() {
        for(int i=0; i<MAXN; ++i){
            fa[i]=i,Rank[i]=0;
        }
    }
    struct Node {
        int x,y,v;
        bool operator<(const Node&b)const {
            return v<b.v;
        }
    } p[MAXN];
    int main() {
        freopen("in.txt","r",stdin);
        int t;
        read(t);
        while(t--) {
            int n,m,r;
            read(n),read(m),read(r);
            init();
            for(int i=0; i<r; ++i) {
                read(p[i].x),read(p[i].y),read(p[i].v);
                p[i].y+=n;
                p[i].v=10000-p[i].v;
            }
            int ans=0;
            sort(p,p+r);
            for(int i=0; i<r; ++i) {
                if(find(p[i].x)==find(p[i].y))
                    continue;
                merge(p[i].x,p[i].y);
                ans+=p[i].v;
            }
            int num=0;
            for(int i=0;i<m+n;++i)
                if(fa[i]==i)++num;
            printf("%d
    ",ans+num*10000);
        }
        return 0;
    }
    
  • 相关阅读:
    [HAL]5.中断里调用HAL_Delay()进入死循环的原因
    【个人吐槽】C、Delphi、C#、java 摘抄
    【常用软件】木木的常用软件点评(2)------VC程序员常用工具篇
    【下位机软件】平均值滤波之鬼斧神工算法
    【vs2013】如何在VS的MFC中配置使用GDI+?
    【MFC】MFC改变对话框中静态文本的字体大小
    【MFC】VC界面绘制双缓存
    【MFC】如何在MFC创建的程序中更改主窗口的属性 与 父窗口 WS_CLIPCHILDREN 样式 对子窗口刷新的影响 与 窗体区域绘制问题WS_CLIPCHILDREN与WS_CLIPSIBLINGS
    Query的选择器中的通配符[id^='code']或[name^='code']
    获取checkbox数组 里面的值
  • 原文地址:https://www.cnblogs.com/foursmonth/p/14144860.html
Copyright © 2011-2022 走看看