a path binary tree sequence node pair adjacent node sequence edge connect a node appear sequence note path need pass rootThe path sum path sum node value pathgiven root binary tree return maximum path sum nonempty path Example 1input root 123output 6explanation the optimal path 2 1 3 path sum 2 1 3 6example 2input root 10920nullnull157output 42explanation the optimal path 15 20 7 path sum 15 20 7 42 ConstraintsThe number nod tree range 1 3 1041000 Nodeval 1000