algorithm - finding the common parent of multiple BitSets java -

i couldn't find proper solution simple question in bitset methods. question find common parent of bitsets, starting left bit. here examples:

011 010 001 common parent: 0  00  010 common parent: 0  00 11 10 common parent: none  1101 111 1100 common parent: 11 

my solution , bitsets, , find correct length looking first set bit on xor of these bitsets. worked cases failed others. have idea involves looping on bitsets happy avoid if have solution.

[i know can presented binary tree, involves memory overhead avoid operating on bitsets , boolean operations (and, or, nor, nand, xor)]

you example this:

    string[] input = {"011","010","001"};      if(input.length==0) return ;     int n=input[0].length();     list<bitset> bitsets = new arraylist<>();     for(string in:input){         // n min length of inputs         n=math.min(n,in.length());         // if start counting indices left, need reverse inputs         string reverse = new stringbuilder(in).reverse().tostring();         // create actual bitsets         bitset b = bitset.valueof(new long[] { long.parselong(reverse, 2) });         bitsets.add(b);     }      for(int i=0;i<n;i++){         boolean equals=true;         for(int j=1;j<bitsets.size();j++)             equals &= bitsets.get(j-1).get(i)==bitsets.get(j).get(i);         if(equals)             system.out.print(bitsets.get(0).get(i)?"1":"0");         // can print indices if needed.     } 

i wrote few comments in code. hope helps!