nyoj 412-Same binary weight (bitset ,to_ulong())

412-Same binary weight

内存限制:64MB
时间限制:0ms
特判: No

通过数:2
提交数:3
难度:3

题目描述:

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.

输入描述:

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

输出描述:

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

样例输入:

复制

1717
4
7
12
555555

样例输出:

1718
8
11
17
555557

C/C++  AC：

 #include <iostream>
 #include <algorithm>
 #include <cstring>
 #include <cstdio>
 #include <cmath>
 #include <stack>
 #include <set>
 #include <map>
 #include <queue>
 #include <climits>
 #include <bitset>
 #define PI 3.1415926

 using namespace std;
 const int MY_MAX = ;
 int N, M;

 int main()
 {
     while (cin >>N)
     {
         bitset <> A(N);
         int pos = , cnt = ;
         for (int i = ; i <= ; ++ i)
         {
             if (A[i] && !A[i + ])
             {
                 A[i] = , A[i + ] = ;
                 pos = i;
                 break;
             }
             if (A[i])
                 cnt ++;
         }

         for (int i = ; i < pos; ++ i)
         {
             if (cnt)
             {
                 A[i] = ;
                 cnt --;
             }
             else
                 A[i] = ;
         }
         printf("%d\n", A.to_ulong());
     }
 }