508. Black-white balls

 1 #include <iostream>
 2 #include <string.h>
 3 #include <string>
 4 #include <fstream>
 5 #include <algorithm>
 6 #include <stdio.h>
 7 #include <vector>
 8 #include <queue>
 9 #include <set>
10 #include <cmath>
11 using namespace std;
12 const double eps = 1e-8;
13 const double pi=acos(-1.0);
14 const int INF=0x7fffffff;
15 unsigned long long uINF = ~0LL;
16 #define MAXN 1007
17 typedef long long LL;
18 LL c[51][51];
19 void init()
20 {
21     memset(c,0,sizeof(c));
22     c[0][0]=1;
23     for(LL i=1;i<=50;i++)
24     {c[i][0]=1;
25     for(LL j=1;j<=i;j++)
26     c[i][j]=c[i-1][j]+c[i-1][j-1];
27     }
28 
29 }
30 int n,l1,l2,p,l;
31 bool check(int s,int e)
32 {
33     int k;double P=0,per=(double)p/100;
34     for(k=s;k<=e;k++)
35         {
36             double temp=(double)c[k][l1]/(double)c[n][l]*(double)c[n-k][l2];
37             P+=temp/(double)(n+1)*(double)(l+1);
38 
39             //cout<<P<<' '<<per<<endl;
40             if(P>per)return true;
41             else if(fabs(P-per)<eps)return true;
42         }
43         return false;
44 }
45 int main()
46 {
47     init();
48 
49     while(scanf("%d%d%d%d",&n,&l1,&l2,&p)!=EOF)
50     {
51         l=l1+l2;
52         int len=INF;
53         int ans1=l1,ans2=n-l2;
54         if(p!=100)
55         for(int i=0;i<=n;i++)
56         for(int j=i;j<=n;j++)
57         {
58         if(j-i+1>=len)continue;
59         if(check(i,j))
60         {
61             ans1=i;ans2=j;len=j-i+1;
62         }
63         }
64         printf("%d %d\n",ans1,ans2);
65     }
66 
67     return 0;
68 }

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posted @ 2013-07-29 15:57  TO_Asia  阅读(243)  评论(0编辑  收藏  举报