Bottom View of Binary Tree

Author: ankit-tyagi

Tree/Bottom View of Binary Tree.cpp

@@ -0,0 +1,140 @@
+// C++ Program to print Bottom View of Binary Tree
+#include<bits/stdc++.h>
+using namespace std;
+// Tree node class
+struct Node
+{
+    int data; //data of the node
+    Node *left, *right; //left and right references
+    // Constructor of tree node
+    Node(int key)
+    {
+        data = key;
+        left = right = NULL;
+    }
+};
+// Method that prints the bottom view.
+void bottomView(Node *root);
+/* Driver program to test size function*/
+int main()
+{
+  int t;
+  struct Node *child;
+  scanf("%d", &t);
+  while (t--)
+  {
+     map<int, Node*> m;
+     int n;
+     scanf("%d",&n);
+     struct Node *root = NULL;
+     while (n--)
+     {
+        Node *parent;
+        char lr;
+        int n1, n2;
+        scanf("%d %d %c", &n1, &n2, &lr);
+        if (m.find(n1) == m.end())
+        {
+           parent = new Node(n1);
+           m[n1] = parent;
+           if (root == NULL)
+             root = parent;
+        }
+        else
+           parent = m[n1];
+        child = new Node(n2);
+        if (lr == 'L')
+          parent->left = child;
+        else
+          parent->right = child;
+        m[n2]  = child;
+     }
+     bottomView(root);
+     cout << endl;
+  }
+  return 0;
+}
+
+
+/*This is a function problem.You only need to complete the function given below*/
+/* Tree node class
+struct Node
+{
+    int data; //data of the node
+    Node *left, *right; //left and right references
+    // Constructor of tree node
+    Node(int key)
+    {
+        data = key;
+        left = right = NULL;
+    }
+}; */
+// Method that prints the bottom view.
+
+int height(Node* root)
+{
+    int l =0,r=0;
+    if(root == NULL)
+        return 0;
+    if(root->left)
+        l = height(root->left);
+    if(root->right)
+        r = height(root->right);
+    
+    return ((l>r)?l:r)+1;
+}
+
+void findbottomview(Node* root, int h, int current_distance, int width[])
+{
+    if(root == NULL)
+        return;
+    
+    width[h+current_distance-1] = root->data;
+    //cout<<"root data"<<root->data<< " and value is "<<width[h+current_distance-1]<<" also "<<h+current_distance-1;
+
+    if(root->left)
+        findbottomview(root->left, h, current_distance-1, width);
+    
+    if(root->right)
+        findbottomview(root->right, h, current_distance+1, width);
+       
+    
+}
+
+void bottomView(Node *root)
+{
+
+    if(root == NULL)
+        return;
+    int totalheight = 0;
+    totalheight = height(root);
+    int h = 2*totalheight -1;
+    int width[h];
+    //cout<<" totalheight & h = "<<totalheight<<h;
+    for(int i=0;i<h;i++)
+    {
+        width[i] = INT_MIN;
+    }
+    findbottomview(root,totalheight,0,width);
+
+    //cout<<"out of the loop";
+
+    for(int i=0;i<h;i++)
+    {
+        //cout<<" value of i "<<i<<"   ";
+        if(width[i] == INT_MIN)
+            continue;
+        cout<<width[i]<<" ";    
+    }
+   // Your Code Here
+}
+
+
+/* 
+For Input:
+2
+6
+0 1 L 0 2 R  1 3 L 1 4 R  2 5 L 2 6 R  
+6
+0 1 L 0 2 R  1 3 L 1 4 R  2 5 L 2 6 R
+*/