DeleteNodeinaBST

Author: FeiCoding

(#450)DeleteNodeinaBST/DeleteNodeinaBST.java

@@ -0,0 +1,30 @@
+class Solution {
+    public TreeNode deleteNode(TreeNode root, int key) {
+        if(root == null) return root;
+        if(root.val == key){
+            if(root.left == null) return root.right;
+            if(root.right == null) return root.left;
+            TreeNode succ = findSucessor(root);
+            root.val = succ.val;
+            root.right = deleteNode(root.right, succ.val);
+            return root;
+        }
+        else if(root.val < key){
+            root.right = deleteNode(root.right, key);
+        }
+        else{
+            root.left = deleteNode(root.left, key);
+        }
+        return root;
+
+    }
+    
+    private TreeNode findSucessor(TreeNode node){
+        TreeNode cur = node.right;
+        while(cur != null && cur.left != null){
+            cur = cur.left;
+        }
+        return cur;
+    }
+    
+}