題解:
每個籃子的選擇概率都是 1/m,所以可以每一次投球進球概率爲 p*1/m+...+p*1/m = p,即每個球的得分概率都是一樣的,可以通過公式獲得。
#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <stack>
#include <cmath>
#include <deque>
#include <queue>
#include <list>
#include <set>
#include <map>
#pragma comment(linker, "/STACK:1024000000,1024000000")
#define line printf("---------------------------\n")
#define mem(a, b) memset(a, b, sizeof(a))
#define pi acos(-1)
using namespace std;
typedef long long ll;
const double eps = 1e-9;
const int inf = 0x3f3f3f3f;
const int mod = 1e9+7;
const int maxn = 100+10;
int main(){
int t, cas = 1;
scanf("%d", &t);
while(t--){
double n, m, k, p;
scanf("%lf %lf %lf %lf", &n, &m, &k, &p);
printf("Case %d: %lf\n", cas++, n*k*p);
}
}