HDU 5090 Game with Pearls【贪心||模拟||二分匹配】

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Game with Pearls

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)

Total Submission(s): 1923    Accepted Submission(s): 677



Problem Description
Tom and Jerry are playing a game with tubes and pearls. The rule of the game is:

1) Tom and Jerry come up together with a number K. 

2) Tom provides N tubes. Within each tube, there are several pearls. The number of pearls in each tube is at least 1 and at most N. 

3) Jerry puts some more pearls into each tube. The number of pearls put into each tube has to be either 0 or a positive multiple of K. After that Jerry organizes these tubes in the order that the first tube has exact one pearl, the 2nd tube has exact 2 pearls, …, the Nth tube has exact N pearls.

4) If Jerry succeeds, he wins the game, otherwise Tom wins. 

Write a program to determine who wins the game according to a given N, K and initial number of pearls in each tube. If Tom wins the game, output “Tom”, otherwise, output “Jerry”.
 

Input
The first line contains an integer M (M<=500), then M games follow. For each game, the first line contains 2 integers, N and K (1 <= N <= 100, 1 <= K <= N), and the second line contains N integers presenting the number of pearls in each tube.
 

Output
For each game, output a line containing either “Tom” or “Jerry”.
 

Sample Input
2 5 1 1 2 3 4 5 6 2 1 2 3 4 5 5
 

Sample Output
Jerry Tom
 

Source
2014上海全国邀请赛——题目重现(感谢上海大学提供题目)



题目大意:

Tom和Jerry玩游戏。

Tom给定N个管子,里面有一些珍珠。

Jerry可以往里面放一些珍珠,必须的K的倍数,或者选择不放。

最后将管子排序,如果能使得第i个管子里刚好有i颗珍珠,则Jerry赢得胜利,否则Tom赢。


解题思路:

一、贪心:

将N个管子按管内的珍珠数量升序排序。

对每个管子进行遍历,如果第i个管子内的珍珠刚好等于i,则进行下一个循环,

如果当前管内珍珠数量<i,则加上k个珍珠,重新对剩余未选择的管子进行排序。

如果当前管内珍珠数量>i,则说明不满足条件,即最少的珍珠数量已经大于i。


二、模拟:

用num数组记录每个数共有几种可能被组成出现。

例如:

4 3

1  1  2  3

num[1]=2,num[2]=1,num[3]=1,num[4]=2

从1到N遍历,如果num[i]不为0,说明有管子可以放在第i个位置,管内珍珠数量为i,

那么之后的num[i+n*k](i+n*k<N , n=0,1,2,...)应该相应的减少1,即组成的可能性减少1。

如果num[i]==0,则说明没有可以构成i的管子存在了,Tom胜出。


前两个解题思路参考-》》http://www.cnblogs.com/Enumz/p/4071631.html


三、二分匹配:

以第二个样例为例:



建边时,我们定义edge[j][i],表示第i个管子可以放j个珍珠。

二分匹配时,我们从珍珠数量出发。

如果第i个管子没被使用,那么我们就把当前的n个珍珠放在第i个管子里。

如果第i个管子被使用了,我们就查找其他管子是否可以放。

最后所有珍珠都可以被放置,即二分图里的最大匹配,恰好count==N,

那么就是Jerry胜利,否则Tom胜利。



/*贪心*/#include <cstdio>#include <algorithm>using namespace std;const int maxn = 110;int num[maxn];int n,k;int main(){int m,i;bool flag;scanf("%d",&m);while(m--){scanf("%d%d",&n,&k);for(i=1;i<=n;++i)scanf("%d",&num[i]);flag=false;sort(num+1,num+n+1);//下标从1开始,注意排序的起始地址和范围 for(i=1;i<=n;++i){if(num[i]!=i){if(num[i]>i){flag=true;break;}num[i]+=k;sort(num+i,num+n+1);--i;//要--i,因为下次循环前要执行++i }}if(flag) printf("Tom\n");else printf("Jerry\n");}return 0;}


/*模拟*/ #include <cstdio>#include <cstring>const int maxn = 110;int num[maxn];int n,k;int main(){int m,i,j,a;bool flag;scanf("%d",&m);while(m--){scanf("%d%d",&n,&k);memset(num,0,sizeof(num));for(i=1;i<=n;++i){scanf("%d",&a);for(j=a;j<=n;j+=k)num[j]++;}flag=false;for(i=1;i<=n;++i){if(!num[i]){flag=true;break;}else{for(j=i;j<=n;j+=k)num[j]--;}}if(flag) printf("Tom\n");else printf("Jerry\n");}return 0;}



/*二分匹配*/ #include <cstdio>#include <cstring>const int maxn = 110;bool edge[maxn][maxn],vis[maxn];int num[maxn],a;int n,k,count;void init(){int i,j,a;memset(edge,0,sizeof(edge));memset(num,-1,sizeof(num));for(i=1;i<=n;++i){scanf("%d",&a);for(j=a;j<=n;j+=k)//注意是edge[j][i],第i个盒子可以放j个珍珠 edge[j][i]=true;}}bool find(int p){int i;for(i=1;i<=n;++i)//遍历管子 {if(edge[p][i]==true&&!vis[i]){vis[i]=true;if(num[i]==-1||find(num[i]))//如果找到管子可以放,则把p个珍珠放在这个管子里。 {num[i]=p;return true;}}}return false;}void hungry(){int i;for(i=1;i<=n;++i)//以珍珠数量去找管子 {memset(vis,0,sizeof(vis));if(find(i))count++;}}int main(){int m,i;scanf("%d",&m);while(m--){scanf("%d%d",&n,&k);init();count=0;hungry();if(count==n) printf("Jerry\n");else printf("Tom\n");}return 0;}






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