interview test

#include <iostream>
#include <cstdio>
using namespace std;
typedef long long LL;
long factorial(long number)
{   if(number<=1)
        return 1;
    else
        return number*factorial(number-1);
}

int combinator(int n,int m)
{   int temp;
    if(n>m)
    {
        return factorial(n)/(factorial(m)*factorial(n-m));
    }
    else if(n==m)
    {

        return  1;
    }
    else{
        return 0;
    }

}
double round(double number, unsigned int bits) {
    LL integerPart = number;
    number -= integerPart;
    for (unsigned int i = 0; i < bits; ++i)
        number *= 10;
    number = (LL) (number + 0.5);
    for (unsigned int i = 0; i < bits; ++i)
        number /= 10;
    return integerPart + number;
}

int main()
{
    int n;
    int m;
    cin>>n>>m;
    cout<<combinator(n,1)<<endl;
    cout<<combinator(m,1)<<endl;
    float x=(float)(combinator(m,2)*2)/combinator(n+m,2)+(float)(combinator(n,1)*combinator(m,1))/combinator(n+m,2);
    cout<<x<<endl;
    float t=(float)m/x;
    cout<<t<<endl;
    printf("%.1f\n", round(t, 1));
    return 0;
}

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转载自blog.csdn.net/zhoumingsong123/article/details/78294345