Card Game Cheater（贪心+二分匹配）

Card Game Cheater

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 1566    Accepted Submission(s): 822

Problem Description

Adam
and Eve play a card game using a regular deck of 52 cards. The rules
are simple. The players sit on opposite sides of a table, facing each
other. Each player gets k cards from the deck and, after looking at
them, places the cards face down in a row on the table. Adam’s cards are
numbered from 1 to k from his left, and Eve’s cards are numbered 1 to k
from her right (so Eve’s i:th card is opposite Adam’s i:th card). The
cards are turned face up, and points are awarded as follows (for each i ∈
{1, . . . , k}):

If Adam’s i:th card beats Eve’s i:th card, then Adam gets one point.

If Eve’s i:th card beats Adam’s i:th card, then Eve gets one point.

A
card with higher value always beats a card with a lower value: a three
beats a two, a four beats a three and a two, etc. An ace beats every
card except (possibly) another ace.

If the two i:th cards
have the same value, then the suit determines who wins: hearts beats all
other suits, spades beats all suits except hearts, diamond beats only
clubs, and clubs does not beat any suit.

For example, the ten of spades beats the ten of diamonds but not the Jack of clubs.

This
ought to be a game of chance, but lately Eve is winning most of the
time, and the reason is that she has started to use marked cards. In
other words, she knows which cards Adam has on the table before he turns
them face up. Using this information she orders her own cards so that
she gets as many points as possible.

Your task is to, given Adam’s and Eve’s cards, determine how many points Eve will get if she plays optimally.

 

Input

There
will be several test cases. The first line of input will contain a
single positive integer N giving the number of test cases. After that
line follow the test cases.

Each test case starts with a line
with a single positive integer k <= 26 which is the number of cards
each player gets. The next line describes the k cards Adam has placed on
the table, left to right. The next line describes the k cards Eve has
(but she has not yet placed them on the table). A card is described by
two characters, the first one being its value (2, 3, 4, 5, 6, 7, 8 ,9,
T, J, Q, K, or A), and the second one being its suit (C, D, S, or H).
Cards are separated by white spaces. So if Adam’s cards are the ten of
clubs, the two of hearts, and the Jack of diamonds, that could be
described by the line

TC 2H JD

 

Output

For
each test case output a single line with the number of points Eve gets
if she picks the optimal way to arrange her cards on the table.

 

Sample Input

3
1
JD
JH
2
5D TC
4C 5H
3
2H 3H 4H
2D 3D 4D

 

Sample Output

1
1
2

题目大意：

a和b手上都有n张牌,b的一张牌赢了a的一张牌,b就得一分，问b能得多少分。

 题解：两种解法，贪心+二分匹配；

二分最大匹配代码：

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<cmath>
 #include<algorithm>
 #define mem(x,y) memset(x,y,sizeof(x))
 using namespace std;
 const int INF=0x3f3f3f3f;
 const int MAXN=;
 struct Node{
     int v;
 }a[MAXN],b[MAXN];
 int mp[MAXN][MAXN];
 int vis[MAXN],usd[MAXN];
 int N;
 int getnum(char *s,Node &temp){
     int x=;
     if(s[]=='A')x=;
     else if(s[]=='T')x=;
     else if(s[]=='J')x=;
     else if(s[]=='Q')x=;
     else if(s[]=='K')x=;
     else if(s[]>=''&&s[]<='')x=s[]-'';
     x=x*;
     if(s[]=='C')x+=;
     else if(s[]=='D')x+=;
     else if(s[]=='S')x+=;
     else if(s[]=='H')x+=;
     temp.v=x;
     }
 bool dfs(int u){
     for(int i=;i<=N;i++){
         if(!vis[i]&&mp[u][i]){
             vis[i]=;
             if(!usd[i]||dfs(usd[i])){
                 usd[i]=u;
                 return true;
             }
         }
     }
     return false;
 }
 int main(){
     int T;
     char s[];
     scanf("%d",&T);
     while(T--){
         mem(mp,);
         scanf("%d",&N);
         for(int i=;i<=N;i++){
             scanf("%s",s);
             getnum(s,a[i]);
         }
         for(int i=;i<=N;i++){
             scanf("%s",s);getnum(s,b[i]);
             for(int j=;j<=N;j++)
                 if(b[i].v>a[j].v)mp[i][j]=;
         }
         mem(usd,);
         int ans=;
         for(int i=;i<=N;i++){
             mem(vis,);
             if(dfs(i))ans++;
         }
         printf("%d\n",ans);
     }
     return ;
 }

贪心：

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<cmath>
 #include<algorithm>
 #define mem(x,y) memset(x,y,sizeof(x))
 using namespace std;
 typedef long long LL;
 const int INF=0x3f3f3f3f;
 int a[],b[];
 char s[];
 int getnum(){
     int x=;
     if(s[]=='A')x=;
     else if(s[]=='T')x=;
     else if(s[]=='J')x=;
     else if(s[]=='Q')x=;
     else if(s[]=='K')x=;
     else if(s[]>=''&&s[]<='')x=s[]-'';
     x=x*;
     if(s[]=='C')x+=;
     else if(s[]=='D')x+=;
     else if(s[]=='S')x+=;
     else if(s[]=='H')x+=;
      return x;
 }
 int main(){
     int T,N;
     scanf("%d",&T);
     while(T--){
         scanf("%d",&N);
         for(int i=;i<N;i++){
             scanf("%s",s);
             a[i]=getnum();
         }
         for(int i=;i<N;i++){
             scanf("%s",s);
             b[i]=getnum();
         }
     //    for(int i=0;i<N;i++)printf("%d ",a[i]);puts("");
     //    for(int i=0;i<N;i++)printf("%d ",b[i]);puts("");
         sort(a,a+N);sort(b,b+N);
         int ans=;
         for(int i=,j=;i<N&&j<N;){
             if(b[i]>=a[j]){
                 i++;j++;ans++;
             }
             else i++;
         }
         printf("%d\n",ans);
     }
     return ;
 }