Big Number
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 31296 Accepted Submission(s):
14539
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
Recommend
一道和数学有关的题，必须用到一个数学公式，一个数n的位数等于 log10（n）+1 。
题意：输入n，求n！是一个几位数。
附上代码：
1 #include <iostream> 2 #include <cstdio> 3 #include <cmath> 4 using namespace std; 5 6 int main() 7 { 8 int n,i,m; 9 double s; 10 scanf("%d",&n); 11 while(n--) 12 { 13 s=0.0; 14 scanf("%d",&m); 15 for(i=1; i<=m; i++) 16 s+=(log10(i)); 17 printf("%d ",(int)s+1); 18 } 19 return 0; 20 21 }