link:http://codeforces.com/contest/345/problem/A

写完这道题目才发现这场比赛只能用Ada语言提交==

好吧,逗我玩呢

考的是数学期望公式,二项分布的期望E=np

C++代码:(我可不会Ada……=_=)

 #include <cstdio>
 #include <cstdlib>
 #include <iostream>
 #include <cstring>
 using namespace std;
 int main(void)
 {
   ];
   double p;
   #ifndef ONLINE_JUDGE
   freopen("in.txt", "r", stdin);
   #endif // ONLINE_JUDGE
   while (~scanf("%s%lf", a, &p))
   {
     int len = strlen(a);
     ;
     ;
     ; i < len; ++i)
     {
       ') cnt++;
       else if (a[i] == '?') cnt1++;
     }
     double Cnt = (double)cnt + p * (double)cnt1;
     printf("%.5lf\n", Cnt/(double)len);
   }

   ;
 }

从今天起,每天一到两题。

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