Cows and Cars
题意:给你三个整数,分别代表,cow的数目,car的数目,door的数目,情景为:玩一个游戏,初始时你选择一条门,判断门后是不是为car,但是主持人不会开门,让你选择时候改变选择,当你确认后,再打开门抽中car的概率;A、当第一次选择时为cow,那么概率为cow / ( cow + car ) * car / ( cow + car - door - 1 )。这里是当且仅当打开最后一条门时;
B、当第一次选择时为car , 那么概率为car / ( cow + car ) * ( car - 1 ) / ( cow + car - door - 1 ) ;
#include<map>
#include<set>
#include<list>
#include<cmath>
#include<ctime>
#include<deque>
#include<stack>
#include<bitset>
#include<cstdio>
#include<vector>
#include<cstdlib>
#include<cstring>
#include<iomanip>
#include<numeric>
#include<sstream>
#include<utility>
#include<iostream>
#include<algorithm>
#include<functional>
using namespace std ;
int main()
{
double cow , car , door ;
while( cin >> cow >> car >> door )
cout << setprecision( 5 ) << fixed << ( cow + car - 1 ) * car / (( cow + car ) * ( cow + car - door - 1 ) ) << endl ;
return 0;
}
补充:web前端 , HTML/CSS ,