Same binary weight

 

Same binary weight

时间限制：300 ms  |  内存限制：65535 KB

难度：3

 

描述

The binary weight of a positive  integer is the number of 1's in its binary representation.for example,the decmial number 1 has a binary weight of 1,and the decimal number 1717 (which is 11010110101 in binary) has a binary weight of 7.Give a positive integer N,return the smallest integer greater than N that has the same binary weight as N.N will be between 1 and 1000000000,inclusive,the result is guaranteed to fit in a signed 32-bit interget.

 

输入

The input has multicases and each case contains a integer N.

输出

For each case,output the smallest integer greater than N that has the same binary weight as N.

样例输入

1717
4
7
12
555555

样例输出

1718
8
11
17
555557

这道题的解，关键是求出n的二进制数最末位0和1的位数：

#include<iostream>
#include<cstdio>

using namespace std;

int main()
{
  int n,i,n0,cnt1,cnt2,k,l,N;

  while(scanf("%d",&n)!=EOF)
  {
   cnt1=0;
   N=n;
   while(n)
   {
    if(n%2!=0)
     break;
      cnt1++;
    n/=2;
   }
   cnt2=cnt1;
   while(n)
   {
    if(n%2==0)
     break;
       cnt2++;
    n/=2;
   }
   k=l=1;
   for(i=1; i<=cnt1; i++)
    k*=2;
     k-=1;
   for(i=1; i<=cnt2-cnt1-1; i++)
    l*=2;
      n0=k+l;
   printf("%d\n",n0+N);
  }
  return 0;
}