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 = 35;
int N, M;

int main()
{
    while (cin >>N)
    {
        bitset <32> A(N);
        int pos = 32, cnt = 0;
        for (int i = 0; i <= 32; ++ i)
        {
            if (A[i] && !A[i + 1])
            {
                A[i] = 0, A[i + 1] = 1;
                pos = i;
                break;
            }
            if (A[i])
                cnt ++;
        }

        for (int i = 0; i < pos; ++ i)
        {
            if (cnt)
            {
                A[i] = 1;
                cnt --;
            }
            else
                A[i] = 0;
        }
        printf("%d\n", A.to_ulong());
    }
}