LINK:HDU 1018 题意:求n!的位数~ 由于n!最后得到的数是十进制,故对于一个十进制数,求其位数可以对该数取其10的对数,最后再加1~ 易知:n!=n*(n-1)*(n-2)*......*3*2*1 ∴lg(n!)=lg(n)+lg(n-1)+lg(n-2)+......+lg(3)+lg(2)+lg(1); 代码: #include <iostream> #include <cstdio> #include <cmath> using namespace…

1. 利用数学公式lg(n!)=lg(2)+lg(3)+....+lg(n) 求解 2.…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1018 解题报告:输入一个n,求n!有多少位. 首先任意一个数 x 的位数 = (int)log10(x) + 1; 所以n!的位数 = (int)log10(1*2*3*.......n) + 1; = (int)(log10(1) + log10(2) + log10(3) + ........ log10(n)) + 1; #include<cstdio> #include<cstrin…

Big Number 题意:算n!的位数. 题解:对于一个数来算位数我们一般都是用while去进行计算,但是n!这个数太大了,我们做不到先算出来在去用while算位数. while(a){ cnt++; a/=; } 将一个数对取10对数(取整),然后再加一就是这个数的位数,然后我们在算n!的时候每次对10取对数就好了. #include<iostream> #include<cmath> using namespace std; int main() { ios::sync_wi…

Big Number Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 21106    Accepted Submission(s): 9498 Problem Description In many applications very large integers numbers are required. Some of these…

Problem Description Inmany applications very large integers numbers are required. Some of theseapplications are using keys for secure transmission of data, encryption, etc.In this problem you are given a number, you have to determine the number ofdig…

Big Number Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 34084    Accepted Submission(s): 16111 Problem Description In many applications very large integers numbers are required. Some of these…

Big Number Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 40262    Accepted Submission(s): 19637 Problem Description In many applications very large integers numbers are required. Some of these…

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…

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…