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最新推荐文章于 2021-02-26 21:51:37 发布

原创最新推荐文章于 2021-02-26 21:51:37 发布 · 943 阅读

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#ACM题解报告 #概率

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弱智概率题，不屑写解析。

#include <iostream>
#include <iomanip>
#include <math.h>

using namespace std;

#define pi acos(-1.0)

double m, n, t, c;//坑！！

double calc_2(double m, double n, double t, double c)
{
    return (t - c)*c*((m - 1)*(n) +(m) *(n - 1)) + c*c / 2.0*(m + n - 2) * 2;
}

double calc_3()
{
    return (m - 1)*(n - 1) * c * c *(1.0 - pi/4);
}

double calc_4()
{
    return (m - 1)*(n - 1) * pi * c * c / 4.0;
}

int main()
{
    int T;
    cin >> T;//一开始竟然两个变量重名了。。
    for (int i = 1; i <= T; i++)
    {
        cin >> m >> n >> t >> c;
        cout << "Case " << i << ":" << endl;
        double s = m * n * t * t;
        cout << "Probability of covering 1 tile  = " << fixed << setprecision(4) << (1 - (calc_2(m, n, t, c) + calc_3() + calc_4()) / s) * 100 << "%" << endl;
        cout << "Probability of covering 2 tiles = " << fixed << setprecision(4) << calc_2(m, n, t, c) * 100 / s << "%" << endl;
        cout << "Probability of covering 3 tiles = " << fixed << setprecision(4) << calc_3() * 100 / s << "%" << endl;
        cout << "Probability of covering 4 tiles = " << fixed << setprecision(4) << calc_4() * 100 / s << "%" << endl;
        cout << endl;
    }
}