PROBLEM DESCRIPTION
Given a root node reference of a BST and a key, delete the node with the given key in the BST. Return the root node reference (possibly updated) of the BST.
SOLUTION
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class Solution {
public TreeNode deleteNode(TreeNode root, int key) {
if(root == null) return null;
if(root.val == key){
//No child
if(root.left == null && root.right == null){
return null;
}
//Only left child
if(root.left == null && root.right != null){
return root.right;
}
//Only right child
if(root.left != null && root.right == null){
return root.left;
}
//Two children
int max = getMaxValueInBST(root.left);
root.val = max;
root.left = deleteNode(root.left, max);
}
if(key < root.val){
root.left = deleteNode(root.left, key);
}
if(key > root.val){
root.right = deleteNode(root.right, key);
}
return root;
}
public int getMaxValueInBST(TreeNode root){
while(root.right != null){
root = root.right;
}
return root.val;
}
}