Tree Traversal,Verticalorder,topview

Author: keshavsingh3197

HackerRank/Data Structure/Tree/Traversal/inorder.py

@@ -1,5 +1,5 @@
-def display(head):
+def inorder(head):
     if head:
-        display(head.left)
+        inorder(head.left)
         print(head.data)
-        display(head.right)
+        inorder(head.right)

HackerRank/Data Structure/Tree/Traversal/postorder.py

@@ -1,5 +1,5 @@
 def postorder(head):
     if head:
-        display(head.left)
-        display(head.right)
+        postorder(head.left)
+        postorder(head.right)
         print(head.data)

HackerRank/Data Structure/Tree/Traversal/preorder.py

@@ -1,5 +1,5 @@
 def preorder(head):
     if head:
         print(head.data)
-        display(head.left)
-        display(head.right)
+        preorder(head.left)
+        preorder(head.right)

HackerRank/Data Structure/Tree/Traversal/topView.py

@@ -0,0 +1,15 @@
+# https://www.hackerrank.com/challenges/tree-top-view/problem
+def topView(root):
+    def fun(node, depth, pos):
+        if node is None:
+            return
+        fun(node.left, depth+1, pos-1)
+        fun(node.right, depth+1, pos+1)
+        if (pos in ans and depth<ans[pos][0]) or pos not in ans:
+            ans[pos] = (depth,node)
+
+    ans = {}
+    fun(root,0,0)
+    keys = sorted(ans.keys())
+    for key in keys:
+        print(ans[key][1].data, end = ' ')

HackerRank/Data Structure/Tree/Traversal/vertical order.py

@@ -0,0 +1,12 @@
+def vertical(head,hd,m):
+    if head is None:
+        return
+    if hd not in m:
+        m[hd]=head.data
+    vertical(head.left,hd-1,m)
+    vertical(head.right,hd+1,m)
+m=dict()
+hd=0
+vertical(root,hd,m)
+for i in sorted(m):
+    print(m[i][0])