Added Solution of LeetCode Problem No. 100

Domains/CompetitiveProgramming/Programs/C/LeetCode/Q100.c

@@ -0,0 +1,102 @@
+/*
+===============================================================
+100. Same Tree
+===============================================================
+
+Difficulty: Easy
+Tags: Binary Tree, Depth-First Search, Recursion
+
+---------------------------------------------------------------
+Problem Statement:
+---------------------------------------------------------------
+Given the roots of two binary trees p and q, write a function
+to check if they are the same or not.
+
+Two binary trees are considered the same if they are
+structurally identical and the nodes have the same value.
+
+---------------------------------------------------------------
+Example 1:
+---------------------------------------------------------------
+Input: p = [1,2,3], q = [1,2,3]
+Output: true
+
+---------------------------------------------------------------
+Example 2:
+---------------------------------------------------------------
+Input: p = [1,2], q = [1,null,2]
+Output: false
+
+---------------------------------------------------------------
+Example 3:
+---------------------------------------------------------------
+Input: p = [1,2,1], q = [1,1,2]
+Output: false
+
+---------------------------------------------------------------
+Constraints:
+---------------------------------------------------------------
+- The number of nodes in both trees is in the range [0, 100].
+- -10^4 <= Node.val <= 10^4
+===============================================================
+*/
+
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     struct TreeNode *left;
+ *     struct TreeNode *right;
+ * };
+ */
+
+/**
+ * Function: isSameTree
+ * --------------------
+ * Checks whether two binary trees (p and q) are structurally identical
+ * and have the same node values.
+ *
+ * @param p : Pointer to the root node of the first tree
+ * @param q : Pointer to the root node of the second tree
+ *
+ * @return  : true if both trees are identical, false otherwise
+ */
+
+
+bool isSameTree(struct TreeNode* p, struct TreeNode* q) {
+
+    // Assume both trees are the same initially
+    bool isValid = true;
+
+    // If both nodes are not NULL, compare their values
+    if (p != NULL && q != NULL)
+    {
+        // Check if the current node values are equal
+        if (p->val == q->val)
+        {
+            // Recursively check the left subtrees
+            isValid = isSameTree(p->left, q->left);
+
+            // If left subtrees are not the same, return false immediately
+            if (isValid == false)
+                return false;
+
+            // Recursively check the right subtrees
+            isValid = isSameTree(p->right, q->right);
+        }
+        else
+        {
+            // Node values differ → trees are not the same
+            return false;
+        }
+    }
+    // If one node is NULL and the other is not → trees differ
+    else if (p != NULL || q != NULL)
+    {
+        return false;
+    }
+
+    // Return true only if all comparisons matched
+    return isValid;
+}
+