Driver code
let root = null ; root = AddNode ( root , 2 ) ; root = AddNode ( root , 6 ) ; root = AddNode ( root , 5 ) ; root = AddNode ( root , 3 ) ; root = AddNode ( root , 4 ) ; root = AddNode ( root , 1 ) ; root = AddNode ( root , 7 ) ; let sum = 8 ; TargetPair ( root , sum ) ;