From 69ae08531429f407eb0766e0869eae9561396a15 Mon Sep 17 00:00:00 2001
From: Suraj kumar <surajkrishankumaryadav@gmail.com>
Date: Tue, 13 Oct 2020 22:31:03 +0530
Subject: [PATCH] added a C program to check if two binary trees are identical

---
 isIdentical_binary_tree.cpp | 134 ++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 isIdentical_binary_tree.cpp

diff --git a/isIdentical_binary_tree.cpp b/isIdentical_binary_tree.cpp
new file mode 100644
index 0000000..bca6e61
--- /dev/null
+++ b/isIdentical_binary_tree.cpp
@@ -0,0 +1,134 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+
+
+/*
+two binary trees are said to be identical
+if left subtree of first tree is exactly 
+similar to left subtree of the 2nd tree 
+and right subtree of first tree
+is exactly similar to right subtree
+of 2nd tree for each node of first tree
+*/
+
+
+struct treenode{
+	int value;
+	struct treenode *left;
+	struct treenode *right;
+};
+
+// allocates a node
+struct treenode *getnode()
+{
+	struct treenode *temp;
+	temp = (struct treenode *)malloc(sizeof(struct treenode));
+	temp->left = NULL;
+	temp->right=NULL;
+	return temp;
+}
+
+// This insert is for BST (binary search tree)
+struct treenode *insert(struct treenode *root,int x)
+{
+	struct treenode *p, *q;
+	q = getnode();
+	q->value = x;
+	q->left = NULL;
+	q->right = NULL;
+	
+	if(root == NULL)
+	return (q);
+	
+	p = root;
+	
+	while(1)
+	{
+		if(x<p->value)
+		{
+			if(p->left == NULL)
+			break;
+			p = p->left;
+		}
+		else
+		{
+			if(p->right == NULL)
+			break;
+			p=p->right;
+		}
+	}
+	
+	if(x<p->value)
+	p->left = q;
+	else
+	p->right = q;
+	
+	return (root);
+}
+
+void printInorder(struct treenode *root)
+{
+	if(root==NULL)
+	return;
+	
+	printInorder(root->left);
+	
+	printf("%d ", root->value);
+	
+	printInorder(root->right);
+	
+}
+
+
+int isIdentical(struct treenode *t1, struct treenode *t2)
+{
+	if(t1==NULL && t2 == NULL)
+	return (1);
+	
+	if(t1==NULL) return 0;
+	if(t2==NULL) return 0;
+	
+	if(t1->value == t2->value)
+	if(isIdentical(t1->left,t2->left))
+	if(isIdentical(t1->right,t2->right))
+	return 1;
+	
+	return 0;
+}
+
+int main()
+{
+	
+
+    struct treenode *root2;
+	root2 = getnode();
+	root2->value = 2;
+	root2->left = getnode();
+	root2->left->value = 1;
+	root2->right = getnode();
+	root2->right->value = 4;
+	printInorder(root2);
+	printf("\n");
+	
+	struct treenode *root3;
+	root3 = getnode();
+	root3->value = 2;
+	root3->left = getnode();
+	root3->left->value = 1;
+	root3->right = getnode();
+	root3->right->value = 4;
+	printInorder(root3);
+	printf("\n");
+	
+	if(isIdentical(root2,root3))
+	printf("Yes equal\n");
+	else
+	printf("Not equal\n");
+
+return 0;
+	
+}