hdu 1018 big number (有个组合公式)
来源:互联网 发布:苹果8plus网络设置 编辑:程序博客网 时间:2024/06/16 00:24
因为有个组合公式 所以转了,再慢慢领悟。
Big Number
Time Limit: 20000/10000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 6291 Accepted Submission(s): 2836
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
21020
Sample Output
719
题意就是求一个数阶乘的位数!
#include <stdio.h>#include <math.h>void main(){ int count,var,j; double sum; scanf("%d",&count); while(count--) { sum=0; scanf("%d",&var); for(j=1;j<=var;j++) sum+=log10(j); printf("%d\n",(int)sum+1); }}
这是最简单的方法,但是耗时长,406ms。
好吧!我们换个方法:
这需要组合数学的知识。log10(n!) = log10(sqrt(2 * pi * n)) + n * log10(n / e)
////Problem ID: 1018////Problem Title: ////Run result: Accept////Run time:0MS////Run memory:332KB//////////////////System Comment End//////////////////#include <iostream>#include <cmath>#define PI 3.14159265int n;int num,ans;void solve(){ double t; int i; t = (num*log(num) - num + 0.5*log(2*num*PI))/log(10); ans = t+1; printf("%d\n",ans);}int main(){ while(scanf("%d",&n)!=EOF) { while(n--) { scanf("%d",&num); solve(); } } return 0;}
- hdu 1018 big number (有个组合公式)
- hdu 1018 Big Number(Stirling公式)
- HDU 1018 Big Number(斯特林公式)
- HDU 1018 Big Number(斯特林公式)
- HDU 1018 Big Number(斯特林公式)
- HDU 1018 Big Number 公式= =
- hdu 1018 Big Number (斯特林公式)
- hdu 1018 Big Number(公式求阶乘位数)
- HDU 1018 Big Number(斯特林公式 或 暴力)
- 斯特林公式&1018 Big Number
- hdu 1018 Big Number
- HDU 1018 Big Number
- HDU 1018 - Big Number
- hdu 1018 Big Number
- hdu 1018 Big Number
- HDU 1018 Big Number
- HDU 1018 Big Number
- HDU 1018 Big Number
- 二叉树中序线索化算法
- jxls与jxl(未完)
- mysql学习之一
- 算法导论-矩阵链乘法
- BST二叉查找树的实现与操作
- hdu 1018 big number (有个组合公式)
- 集体智慧编程学习之聚类系统
- “图像处理”常用基本线代知识【备忘】
- In App Purchase Programming Guide(中文版)
- 信号量/互斥的理解
- 【Archived Log】归档日志格式和归档路径之change趣谈
- fopen & fprintf
- RCFileInputFormat的使用方法
- uva10820 - Send a Table(交表)