Delete Node in a BST 2020-12-30 01:13

Problem Description

public static TreeNode deleteNode(TreeNode root, int key) {
    if (root == null) {
        return null;
    }
    if (root.val > key) {
        root.left = deleteNode(root.left, key);
        return root;
    } else if (root.val < key) {
        root.right = deleteNode(root.right, key);
        return root;
    } else {
        if (root.left == null) {
            return root.right;
        } else if (root.right == null) {
            return root.left;
        } else {
            TreeNode result = getMin(root.right);
            result.right = deleteMinAndReturnRoot(root.right);
            result.left = root.left;
            return result;
        }
    }
}

private static TreeNode getMin(TreeNode root) {
    if (root.left == null) {
        return root;
    }
    return getMin(root.left);
}

private static TreeNode deleteMinAndReturnRoot(TreeNode root) {
    if (root.left == null) {
        return root.right;
    }
    root.left = deleteMinAndReturnRoot(root.left);
    return root;
}

henryxi leetcode list

EOF