vector<int> countBits(int num) {
vector<int> cntBits(num+1,0);
cntBits[0] = 0;
cntBits[1] = 1;
for (int i = 2; i <= num; i++){
if(i & 1){ // Odd Number
cntBits[i] = cntBits[i>>1] + 1;
}else{ // Even Number
void complement(int upb, Intstack cell, Intstack result) {
int i = 0, j = 0;
result->size = 0;
/* invariant: j == cell->size || i <= cell->it[j] */
while (i < upb) {
if (j == cell->size || i < cell->it[j]) {
if (cntBits(i) % 2 == 0) putint(i, result);
i++;
} else {
i++;
j++;
}
}
}