give root binary tree level root 1 level child 2 onreturn small level x sum value nod level x maximal Example 1input root 17078nullnulloutput 2explanation level 1 sum 1Level 2 sum 7 0 7level 3 sum 7 8 1so return level maximum sum level 2example 2input root 989null102509869389388nullnullnull32127Output 2 ConstraintsThe number nod tree range 1 104105 Nodeval 105