Next higher number containing equal set bits

NextHigherNumberContainingEqualSetBits.cpp

#include <iostream>
#include <bitset>
using namespace std;

// used char for illustration, use int in practice
typedef unsigned char uint;
const unsigned int SIZE = sizeof(uint) * 8;

void printBitRepresentation(uint x) {
	cout << bitset<SIZE>(x) << endl; 
}

uint getNextHigherNumberContainingEqualSetBits(uint x) {
	if (x == 0) return 0;
	uint a = x & -x;
	uint b = a + x;
	uint r = b | (((x ^ b) >> 2) / a);
	return r;
}

void generateAllSubsets(uint start) {
	printBitRepresentation(start);
	for (uint cur = getNextHigherNumberContainingEqualSetBits(start); cur > start; cur = getNextHigherNumberContainingEqualSetBits(cur))
		printBitRepresentation(cur);
}

int main() {
	generateAllSubsets((1 << (SIZE-1)) - 1);
	return 0;
}