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2013
12-09

HDU 1390 Binary Numbers[解题报告] C++

Binary Numbers

问题描述 :

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.

输入:

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.

输出:

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.

样例输入:

1
13

样例输出:

0 2 3

#include <iostream>
using namespace std;
int main()
{
	int d, n, i, a[32], l, flag;
	cin >> d;
	while (d--)
	{
		cin >> n;
		l = 0;
		while (n)
		{
			a[l++] = n%2;
			n /= 2;
		}
		flag = 1;
		for (i = 0; i < l; i++)
		{
			if(a[i])
				if (flag)
				{
					cout << i;
					flag = 0;
				}
				else 
					cout << " " << i;
		}
		cout<<endl;
	}
	return 0;
}

解题报告转自:http://blog.csdn.net/ysc504/article/details/8251191


  1. #include <cstdio>
    #include <cstring>

    const int MAXSIZE=256;
    //char store[MAXSIZE];
    char str1[MAXSIZE];
    /*
    void init(char *store) {
    int i;
    store['A']=’V', store['B']=’W',store['C']=’X',store['D']=’Y',store['E']=’Z';
    for(i=’F';i<=’Z';++i) store =i-5;
    }
    */
    int main() {
    //freopen("input.txt","r",stdin);
    //init(store);
    char *p;
    while(fgets(str1,MAXSIZE,stdin) && strcmp(str1,"STARTn")==0) {
    if(p=fgets(str1,MAXSIZE,stdin)) {
    for(;*p;++p) {
    //*p=store[*p]
    if(*p<’A’ || *p>’Z') continue;
    if(*p>’E') *p=*p-5;
    else *p=*p+21;
    }
    printf("%s",str1);
    }
    fgets(str1,MAXSIZE,stdin);
    }
    return 0;
    }