zoukankan      html  css  js  c++  java
  • uva 10288 gailv

    Problem F
    
    Coupons
    
    Input: standard input
    
    Output: standard output
    
    Time Limit: 2 seconds
    
    Memory Limit: 32 MB
    
     
    
    Coupons in cereal boxes are numbered 1 to n, and a set of one of each is required for a prize (a cereal box, of course). With one coupon per box, how many boxes on average are required to make a complete set ofn coupons?
    
    Input
    
    Input consists of a sequence of lines each containing a single positive integern, 1<=n<=33, giving the size of the set of coupons. Input is terminated by end of file.
    
    Output
    
    For each input line, output the average number of boxes required to collect the complete set ofn coupons. If the answer is an integer number, output the number. If the answer is not integer, then output the integer part of the answer followed by a space and then by the proper fraction in the format shown below. The fractional part should be irreducible. There should be no trailing spaces in any line of output.
    
    Sample Input
    
    2
    5
    17
    Sample Output
    
    3 
       5
    11 --
       12
       340463
    58 ------

    记得每次求gcd不然会爆掉。 思路:到k张时。我们还有n-k张没有得到。所以我们得到的概率为n-k/n;

    所以到k+1步的期望时n/n-k;

    整理得 n* 1/i(n>i>1)的累加

    #include <iostream>
    #include <string.h>
    #include <stdio.h>
    #include <algorithm>
    using namespace std;
    #define ll long long
    ll gcd(ll n,ll m)
    {
        if(m==0)
            return n;
        return gcd(m,n%m);
    }
    int geth(ll x)
    {
        int ans=0;
        while(x>0)
        {
            x=x/10;
            ans++;
        }
        return ans;
    }
    int main()
    {
        ll  n;
        while(~scanf("%lld",&n))
        {
            
            ll fenmu=1;
            ll temp=1;
            for(int i=1;i<=n;i++)
            {
                temp=gcd(fenmu,i);
                fenmu=fenmu*i/temp;
            }
            ll fenzi=0;
            for(int i=1;i<=n;i++)
            {
                fenzi+=fenmu/i;
                
            }
            fenzi=fenzi*n;
            ll p=gcd(fenzi,fenmu);
            fenzi/=p;
            fenmu/=p;
            ll t=fenzi/fenmu;
            if(fenzi-fenmu*t>0)
            {
                if(t!=0)
                {
                    ll a=geth(t);
                    for(int i=0;i<=a;i++)
                    {cout<<" ";}
                    cout<<fenzi-fenmu*t;
                    ll b=geth(fenzi-fenmu*t);
                    ll c=geth(fenmu);
                    if(b>c)
                        c=b;
                    cout<<endl;
                    cout<<t<<" ";
                    for(int i=1;i<=c;i++)
                    {cout<<"-";}
                    cout<<endl;
                    for(int i=0;i<=a;i++)
                    {cout<<" ";}
                    cout<<fenmu<<endl;
                }
            }
            else
                cout<<t<<endl;
            
        }
        
        
        return 0;
    }
  • 相关阅读:
    SVN为什么比Git更好
    vim的高亮查找操作
    Mac利用PD虚拟机安装Centos7
    学习MapReduce的计算原理
    hadoop-HA高可用集群部署
    HDFS命令操作和高可用
    初识hadoop及伪集群部署
    初步学习nginx
    小记--------maxwell启动失败解决
    小记--------spark资源调度机制源码分析-----Schedule
  • 原文地址:https://www.cnblogs.com/2014slx/p/9538251.html
Copyright © 2011-2022 走看看