public static int findConnectedComponents(List<Long> d) {

    TreeMap<Long, Integer> bitsMap = new TreeMap<>();
    
    int n = d.size();
    int numOfSubsets = 1 << n;
    int res = 0;
    
    for (int i = 0; i < numOfSubsets; i ++) {
        List<Long> subset = new ArrayList<>();
                
        for (int j = 0; j < n; j++) {
            
            int mask = 1 << j;
            if ((i & mask) != 0) { 
                long cur = d.get(j);
                ListIterator<Long> iter = subset.listIterator();
                
                while (iter.hasNext()) {
                    
                    long iterCur = iter.next();
                
//iterate current subset and merge all intersected pairs
//this way there will not be any stragglers left behind
//even if met with similar cases such as {3, 12, 6} subset:
//0011
//1100
//0110
                    
                    if ((iterCur & cur) != 0) {
                        cur |= iterCur;
                        iter.remove();            
                    }
                }
                subset.add(cur);
                        
                if (bitsMap.get(cur) == null) {
                    bitsMap.put(cur, countBits(cur));
                }              
            }
        }

//as we have merged all intersected pairs, 
//the rest are naturally independent components
            
        int components = subset.size();
        
        long subsetRep = 0;
        for (Long l : subset) {
            subsetRep |= l;
        }
        
        Integer countBit = bitsMap.get(subsetRep);
        if (countBit == null) {
            countBit = countBits(subsetRep);
        }
        res += 64 - countBit + components;    
    }
    
    return res;   
}