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
#include <iostream> #include <cstdio> #include <bitset> using namespace std; int main() { int n; while(scanf("%d",&n)!=EOF){ bitset<32> b(n); int j; int cou=0; for(int i=0;i<32;i++){ if(b[i]){ cou++; } if(b[i]&&!b[i+1]){ j=i; b[i]=false; b[i+1]=true; break; } } cou--; for(int k=0;k<cou;k++){ b[k]=true; } for(int k=cou;k<j;k++){ b[k]=false; } printf("%ld\n",b.to_ulong()); //cout<<b.to_ulong()<<endl(); } return 0; }
原文：http://www.cnblogs.com/TWS-YIFEI/p/5903750.html