traversal for binary trees postorder traversal of binary tree analogouslythe postorder traversal for general trees (code fragment can be specialized for binary treesas shown in code fragment code fragment algorithm binarypostorder for performing the postorder traversal of the subtree of binary tree rooted at node expression tree evaluation the postorder traversal of binary tree can be used to solve the expression tree evaluation problem in this problemwe are given an arithmetic expression treethat isa binary tree where each external node has value associated with it and each internal node has an arithmetic operation associated with it (see example )and we want to compute the value of the arithmetic expression represented by the tree algorithm evaluateexpressiongiven in code fragment evaluates the expression associated with the subtree rooted at node of an arithmetic expression tree by performing postorder traversal of starting at in this