HDU 1390 Binary Numbers(数学题)

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1390

Problem Description

Given a positive integer n, find the positions of all 1's in its binary representation. The position of the least significant bit is 0.
Example
The positions of 1's in the binary representation of 13 are 0, 2, 3.
Task
Write a program which for each data set:
reads a positive integer n,
computes the positions of 1's in the binary representation of n,
writes the result.

 

Input

The first line of the input contains exactly one positive integer d equal to the number of data sets, 1 <= d <= 10. The data sets follow.
Each data set consists of exactly one line containing exactly one integer n, 1 <= n <= 10^6.

 

Output

The output should consists of exactly d lines, one line for each data set.
Line i, 1 <= i <= d, should contain increasing sequence of integers separated by single spaces - the positions of 1's in the binary representation of the i-th input number.

 

Sample Input

   
   
   
   

    
    
    
    1
13
   
   
   
   

 

Sample Output

   
   
   
   

    
    
    
    0 2 3
   
   
   
   

 

Source

Central Europe 2001, Practice

题意：

找一个数的二进制中为1的位置！

代码如下：

#include <cstdio>
int a[1000007];
int main()
{
    int n;
    int t;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        int k = 0;
        int l = -1;
        while(n)
        {
            int t = n%2;
            if(t)
            {
                a[++l] = k;
            }
            k++;
            n/=2;
        }
        for(int i = 0; i < l; i++)
        {
            printf("%d ",a[i]);
        }
        printf("%d\n",a[l]);
    }
    return 0;
}