Jillian's Tree Practice Assignment

tree-practice.rb

@@ -15,7 +15,237 @@ def print_infix(node)
   print_infix(node.right)
 end
 
-root = TreeNode.new("+")
-root.left = TreeNode.new("3")
-root.right = TreeNode.new("2")
-print_infix(root)
+# Starting at node root, check if node has children. If so, move down to the next node on the left.
+# Continue down left branch until you reach a node with no children. Print it's parent.
+# Traverse back up the tree, printing parents until root is reached and printed.
+# Traverse down root's right branch doing the same as above.
+def operators(node)
+  return if node == nil
+  operators(node.left)
+  if node.left != nil || node.right != nil
+    print node.value + " "
+  end
+  operators(node.right)
+end
+
+# Starting at root, travel down the left branch until a node with no child is found, and print that node.
+# Go up to it's parent, and down it's right branch, printing any node without a child.
+# Repeat until the right most branch is completed.
+def non_operators(node)
+  return if node == nil
+  non_operators(node.left)
+  if node.left.nil? || node.right.nil?
+    print node.value + " "
+  end
+  non_operators(node.right)
+end
+
+# Method to return the number of leaves.
+def leaves(node)
+  return 1 if /\d+/.match(node.value)
+  return (leaves(node.left) + leaves(node.right))
+end
+
+# Method to return number of operators. Not currently working.
+def ops(node)
+  if node.left.nil? || node.right.nil?
+    return 1 if /[\+\-\*\%\/\.]/.match(node.value)
+  else
+    return (ops(node.left) + ops(node.right))
+  end
+end
+
+
+# Start at root node, print root node
+# print node.left all the way down the branch
+# print node.right all the way up the branch until returned to root
+# print root node's right branch
+# then root.right.left all the way down
+# then root.right.right all the way up
+def print_prefix(node)
+  return if node.nil?
+  print node.value + " "
+  print_prefix(node.left)
+  print_prefix(node.right)
+end
+
+# start at root node, traverse all the way down left until reaching a node with no child.
+# print first node with no child.
+# Go up to parent node, traverse down right branch, print node with no child
+# print parent, go up to parent's parent.
+# print right no child node, print parent
+# repeat until root is printed.
+def print_postfix(node)
+  return if node.nil?
+  print_postfix(node.left)
+  print_postfix(node.right)
+  print node.value + " "
+end
+
+# Starting at root, traverse down tree
+# If node has no children, go up to parent
+# Check if parent is operator, print if so
+# Repeat down all branches
+def operator_found(node, operator)
+ return if node.nil?
+ operator_found(node.left, operator)
+ if !node.left.nil? || !node.left.nil?
+   if node.value == operator
+     print "Yes! '#{node.value}' does appear! "
+   end
+ end
+ operator_found(node.right, operator)
+end
+
+
+#### IN CLASS TEST CASES ####
+# root = TreeNode.new("+")
+# root.left = TreeNode.new("3")
+# root.right = TreeNode.new("2")
+# print_infix(root)
+# puts "\n"
+# operators(root)
+# puts "\n"
+# non_operators(root)
+# puts "\n"
+# print_prefix(root)
+# puts "\n"
+# print_postfix(root)
+# puts "\n"
+# operator_found(root, "+")
+# operator_found(root, "-")
+#
+# puts "\n"
+# puts "\n"
+#
+# new_root = TreeNode.new("+")
+# new_root.left = TreeNode.new("3")
+# new_root.right = TreeNode.new("-")
+# new_root.right.left = TreeNode.new("2")
+# new_root.right.right = TreeNode.new("10")
+# print_infix(new_root)
+# puts "\n"
+# operators(new_root)
+# puts "\n"
+# non_operators(new_root)
+# puts "\n"
+# print_prefix(new_root)
+# puts "\n"
+# print_postfix(new_root)
+# puts "\n"
+# operator_found(new_root, "+")
+# operator_found(new_root, "-")
+#
+# puts "\n"
+# puts "\n"
+#
+# newer_root = TreeNode.new("+")
+# newer_root.left = TreeNode.new("*")
+# newer_root.left.left = TreeNode.new("4")
+# newer_root.left.right = TreeNode.new("3")
+# newer_root.right = TreeNode.new("2")
+# print_infix(newer_root)
+# puts "\n"
+# operators(newer_root)
+# puts "\n"
+# non_operators(newer_root)
+# puts "\n"
+# print_prefix(newer_root)
+# puts "\n"
+# print_postfix(newer_root)
+# puts "\n"
+# operator_found(newer_root, "+")
+# operator_found(newer_root, "-")
+#
+# puts "\n"
+# puts "\n"
+
+newest_root = TreeNode.new("-")
+newest_root.left = TreeNode.new("+")
+newest_root.left.left = TreeNode.new("*")
+newest_root.left.left.left = TreeNode.new("4")
+newest_root.left.left.right = TreeNode.new("3")
+newest_root.left.right = TreeNode.new("2")
+newest_root.right = TreeNode.new("%")
+newest_root.right.left = TreeNode.new("10")
+newest_root.right.right = TreeNode.new("5")
+print_infix(newest_root)
+puts "\n"
+operators(newest_root)
+puts "\n"
+non_operators(newest_root)
+puts "\n"
+print_prefix(newest_root)
+puts "\n"
+print_postfix(newest_root)
+puts "\n"
+operator_found(newest_root, "+")
+operator_found(newest_root, "-")
+puts "\n"
+puts leaves(newest_root)
+puts ops(newest_root)
+
+puts "\n"
+puts "\n"
+
+### ADDITIONAL TEST CASES ###
+# 7 + 9
+# test1 = TreeNode.new("+")
+# test1.left = TreeNode.new("7")
+# test1.right = TreeNode.new("9")
+# print_prefix(test1)
+# puts "\n"
+# print_infix(test1)
+# puts "\n"
+# print_postfix(test1)
+# puts "\n"
+# operators(test1)
+# puts "\n"
+# non_operators(test1)
+# puts "\n"
+# operator_found(test1, "+")
+# operator_found(test1, "-")
+#
+# puts "\n\n"
+#
+# # 4 * 12 / 3
+# # ((4 * 12) / 3)
+# test2 = TreeNode.new("/")
+# test2.left = TreeNode.new("*")
+# test2.left.left = TreeNode.new("4")
+# test2.left.right = TreeNode.new("12")
+# test2.right = TreeNode.new("3")
+# print_prefix(test2)
+# puts "\n"
+# print_infix(test2)
+# puts "\n"
+# print_postfix(test2)
+# puts "\n"
+# operators(test2)
+# puts "\n"
+# non_operators(test2)
+# puts "\n"
+# operator_found(test2, "+")
+# operator_found(test2, "*")
+#
+# puts "\n\n"
+#
+# # 7 - 8 * 2
+# # 7 - (8 * 2)
+# test3 = TreeNode.new("-")
+# test3.left = TreeNode.new("7")
+# test3.right = TreeNode.new("*")
+# test3.right.left = TreeNode.new("8")
+# test3.right.right = TreeNode.new("2")
+# print_prefix(test3)
+# puts "\n"
+# print_infix(test3)
+# puts "\n"
+# print_postfix(test3)
+# puts "\n"
+# operators(test3)
+# puts "\n"
+# non_operators(test3)
+# puts "\n"
+# operator_found(test3, "+")
+# operator_found(test3, "-")