Glass Bead Game

Output one real number, the answer.

Your answer will be considered correct if its absolute or relative error does not exceed $10^{-6}$ . Formally let your answer be $a$ , jury answer be $b$ . Your answer will be considered correct if $\frac{|a-b|}{\max (1,|b|)} \leq 10^{-6}$ .

C++(clang++ 11.0.1) 解法, 执行用时: 3ms, 内存消耗: 468K, 提交时间: 2023-05-03 14:25:09

#include <bits/stdc++.h>
using namespace std;
#define N 105
int n;
double p[N],g;
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++) cin>>p[i];
    for(int i=1;i<=n;i++) for(int j=i+1;j<=n;j++) g+=(p[i]*p[j])/(p[i]+p[j]);
    printf("%.9lf\n",g*2);
}

pypy3 解法, 执行用时: 128ms, 内存消耗: 26976K, 提交时间: 2022-04-18 10:09:57

n = int(input())
ans = 0
p = list(map(float, input().split()))
ans = 0
for i in range(n):
    for j in range(n):
        if i != j:
            ans += p[i]*p[j]/(p[i]+p[j])

print(ans)

Python3 解法, 执行用时: 44ms, 内存消耗: 4544K, 提交时间: 2022-04-21 10:38:34

n=input()
p=list(map(float,input().split()))
ans=0
for i,pi in enumerate(p):
    for j,pj in enumerate(p):
        if i!=j:
            ans+=pi*pj/(pi+pj)
print(ans)

详情