Tree Practice Question
Duration: 2 min
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AI Summary
An AI-generated summary of this video lecture.
The video features an educational lecture by Sanchit Jain Sir from Knowledge Gate, focusing on a C programming problem involving binary trees. The specific task is to complete a function named `maxDepth` which calculates the maximum depth or height of a binary tree, noting that the root is at level 1. The code snippet provided on screen defines the function signature `int maxDepth(struct node* node)`. The instructor walks through the logic, starting with the base case: `if (node == NULL) return 0;`. This condition ensures that if a node does not exist, the depth contribution is zero. Following the base case, the `else` block handles the recursive step. The code calculates the depth of the left subtree using `int lDepth = maxDepth(node->left);` and the right subtree using `int rDepth = maxDepth(node->right);`. The critical part of the lecture is analyzing the final return statements. The code presents a conditional check: `if (lDepth > rDepth) return X; else return Y;`. The instructor explains that to find the total height, one must take the larger of the two subtree depths and add 1 to account for the current node itself. Consequently, the placeholders X and Y must represent the depth of the respective subtrees incremented by one. The question text at the bottom asks: "What should be the values of X and Y so that the function works correctly?". The visible options are (A) X = lDepth, Y = rDepth; (B) X = lDepth + 1, Y = rDepth + 1; (C) X = lDepth - 1, Y = rDepth - 1; and (D) None of the above. The instructor emphasizes that since the depth includes the current node, the value returned must be the subtree depth plus one. He points to the code structure to justify why adding 1 is necessary for the correct calculation of tree height, highlighting the recursive definition where height is 1 + max(left_height, right_height). The watermark "KNOWLEDGEGATE" is visible throughout the screen. The instructor is seated in a black gaming chair, wearing a white t-shirt with the Knowledge Gate logo.
Chapters
0:00 – 1:39 00:00-01:39
The video analyzes a C function `maxDepth` for binary trees. It covers the base case `if (node==NULL) return 0;`, the recursive calculation of `lDepth` and `rDepth`, and the logic to determine the return values X and Y, which must account for the current node's level by adding 1 to the subtree depths. The instructor explains that the height of a node is 1 plus the maximum height of its children, requiring the addition of 1 in the return statement.
The lecture reinforces the recursive definition of tree height, where the height of a node is 1 plus the maximum height of its children, requiring the addition of 1 in the return statement to correctly calculate the total depth.