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.

1717

4

7

12

555555

1718

8

11

17

555557
解题思路  1. 将右起第一个“01”，改变为“10”  2. 将该“01”后面的所有“1”移动至最后

#include <iostream>

#include <string>

#include <bitset>

#include <algorithm>

using namespace std;

int main(){

    int n;

    while(cin >> n){

        bitset<> bitInt(n);

        string strInt =bitInt.to_string();

        int pos = strInt.rfind("");

        swap(strInt[pos],strInt[pos+]);

        if(pos+ < ) sort(strInt.begin()+pos+,strInt.end());

        cout<<bitset<>(strInt).to_ulong()<<endl;

    }

}

string rfind("01")从字符串右边找”01“然后返回”01“的位置

将01后面的1移动到最后相当于对01后面的字符串排序