zoukankan      html  css  js  c++  java
  • hdu1018 Big Number 斯特林公式 求N!的位数。

    Big Number

    Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
    Total Submission(s): 37732    Accepted Submission(s): 18174


    Problem Description
    In many applications very large integers numbers are required. Some of these applications are using keys for secure transmission of data, encryption, etc. In this problem you are given a number, you have to determine the number of digits in the factorial of the number.
     
    Input
    Input consists of several lines of integer numbers. The first line contains an integer n, which is the number of cases to be tested, followed by n lines, one integer 1 ≤ n ≤ 107 on each line.
     
    Output
    The output contains the number of digits in the factorial of the integers appearing in the input.
     
    Sample Input
    2 10 20
     
    Sample Output
    7 19
     
    Source
     
    /**
    题目:Big Number
    链接:http://acm.hdu.edu.cn/showproblem.php?pid=1018
    题意:求n!的位数。
    思路:
    斯特林公式:LL res=(long)( (log10(sqrt(4.0*acos(0.0)*n)) + n*(log10(n)-log10(exp(1.0)))) + 1 );
    注意:当n=1的时候,公式不成立。自己算。
    
    */
    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <cmath>
    #include <algorithm>
    using namespace std;
    typedef long long LL;
    const int mod=1e9+7;
    const int maxn=1e6+5;
    int T, n;
    int main()
    {
        cin>>T;
        while(T--)
        {
            scanf("%d",&n);
            if(n==1){
                printf("1
    "); continue;
            }
            LL res=(long)( (log10(sqrt(4.0*acos(0.0)*n)) + n*(log10(n)-log10(exp(1.0)))) + 1 );
            printf("%lld
    ",res);
        }
        return 0;
    }
  • 相关阅读:
    原生js螺旋运动
    拉美电子游戏市场创收45亿美元
    ZOJ 3229 Shoot the Bullet
    Java的压缩、解压及压缩加密、解密解压 样例
    java环境变量配置
    git在myelispse中的安装
    java注解
    Python测试框架doctest
    python中的协程
    Flask log配置,实现按照日期自动生成日志文件
  • 原文地址:https://www.cnblogs.com/xiaochaoqun/p/6884886.html
Copyright © 2011-2022 走看看