public List<Integer> mergeChunksOfDifferentSize(List<List<Integer>> chunks){
        List<Integer> result = new ArrayList<Integer>();

        int sum[] = new int[chunks.size()+1];
        sum[0] = 0;
        for(int i =1; i < sum.length;i++){
            sum[i] = sum[i-1] + chunks.get(i-1).size();
        }
        
        for(List<Integer> chunk : chunks){
            for(Integer i : chunk){
                result.add(i);
            }
        }
        mergeSort(result,0,chunks.size()-1,sum);
        return result;
    }
Given a list of lists. Each element in the list is sorted. Sort the 
entire list.
Test cases
One or more lists are empty
All elements in one list are smaller than all elements in another list
src/com/interview/array/ChunkMerge.java