17暑假多校联赛1.1 HDU 6033 Add More Zero

Add More Zero

Time Limit: 2000/1000 MS (Java/Others)
Memory Limit: 131072/131072 K (Java/Others)
 

Problem Description

There is a youngster known for amateur propositions concerning several mathematical hard problems.
Nowadays, he is preparing a thought-provoking problem on a specific type of supercomputer which has ability to support calculations of integers between 0 and (2m−1) (inclusive).
As a young man born with ten fingers, he loves the powers of 10 so much, which results in his eccentricity that he always ranges integers he would like to use from 1 to 10k (inclusive).
For the sake of processing, all integers he would use possibly in this interesting problem ought to be as computable as this supercomputer could.
Given the positive integer m, your task is to determine maximum possible integer k that is suitable for the specific supercomputer.
 

Input

The input contains multiple test cases. Each test case in one line contains only one positive integer m, satisfying 1≤m≤105.
 

Output

For each test case, output “Case #x: y” in one line (without quotes), where x indicates the case number starting from 1 and y denotes the answer of corresponding case.
 

Sample Input

164

Sample Output

Case #1: 0Case #2: 19

 
题目网址：http://acm.hdu.edu.cn/showproblem.php?pid=6033
 

分析

题目：给出n，计算2的n次方用科学记数法书写时乘的是10的多少次方，
很简单的题，直接用log函数来写就行
 

代码

#include <bits/stdc++.h>using namespace std;int main(){    int m;    int p=0;    while(~scanf("%d",&m))    {        printf("Case #%d: ",++p);        printf("%.0f\n",floor(m*1.0*(log(2.0)/log(10.0))));    }}