Light OJ 1045 Digits of Factorial(求位数)
2014-05-02 00:50
417 查看
1045 - Digits of Factorial
Factorial of an integer is defined by the following function
f(0) = 1
f(n) = f(n - 1) * n, if(n > 0)
So, factorial of 5 is 120. But in different bases, the factorial may be different. For example, factorial of 5 in base 8 is 170.
In this problem, you have to find the number of digit(s) of the factorial of an integer in a certain base.
Each case begins with two integers n (0 ≤ n ≤ 106) and base (2 ≤ base ≤ 1000). Both of these integers will be given in decimal.
与白书里面推荐的一道UVA题目很像,http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1002
也是利用对数来求位数。
代码:
![]() | PDF (English) | Statistics | Forum |
Time Limit: 2 second(s) | Memory Limit: 32 MB |
f(0) = 1
f(n) = f(n - 1) * n, if(n > 0)
So, factorial of 5 is 120. But in different bases, the factorial may be different. For example, factorial of 5 in base 8 is 170.
In this problem, you have to find the number of digit(s) of the factorial of an integer in a certain base.
Input
Input starts with an integer T (≤ 50000), denoting the number of test cases.Each case begins with two integers n (0 ≤ n ≤ 106) and base (2 ≤ base ≤ 1000). Both of these integers will be given in decimal.
Output
For each case of input you have to print the case number and the digit(s) of factorial n in the given base.Sample Input | Output for Sample Input |
5 5 10 8 10 22 3 1000000 2 0 100 | Case 1: 3 Case 2: 5 Case 3: 45 Case 4: 18488885 Case 5: 1 |
也是利用对数来求位数。
代码:
#include<stdio.h> #include<cmath> using namespace std; double a[1000010]; int main() { freopen("in.txt","r",stdin); a[1]=log(1); for(int i=2;i<=1000000;i++)a[i]=a[i-1]+log(i); int t; scanf("%d",&t); for(int ca=1;ca<=t;ca++) { int n,b; scanf("%d%d",&n,&b); if(n==0) { printf("Case %d: %d\n",ca,1); continue; } double ans=0; printf("Case %d: %.0lf\n",ca,floor(a /log(b*1.0))+1); } return 0; }
相关文章推荐
- light oj1045 - Digits of Factorial (阶乘的位数,,运用对数)
- light oj --Digits of Factorial (一个数的位数问题以及log的公式应用)
- LightOJ1045 Digits of Factorial 求n的阶乘在k进制下的位数
- Light OJ 1045 - Digits of Factorial
- Light OJ:1045 Digits of Factorial(数学+思维+对数)
- Light-oj-1045 lightoj1045 - Digits of Factorial (N!不同进制的位数)
- lightoj 1045 - Digits of Factorial (数学-log运用--阶乘进制位数)
- LightOJ - 1045 Digits of Factorial
- LightOJ 1045 Digits of Factorial
- LightOJ 1045 Digits of Factorial
- LightOJ 1045 I - Digits of Factorial
- lightoj1045 - Digits of Factorial
- LIGHTOJ 1045 - Digits of Factorial 【阶乘取对数】
- lightoj 1045 - Digits of Factorial 【数学】
- lightOJ 1045 Digits of Factorial (数位计数)
- lightoj 1045 - Digits of Factorial
- Jan's LightOJ :: Problem 1045 - Digits of Factorial
- LightOJ 1045 Digits of Factorial(大数进制)
- 【LightOJ】1045 - Digits of Factorial(数论)
- LightOJ 1045 Digits of Factorial【进制问题】