feat: 删除二叉搜索树中的节点

Author: sl1673495

二叉树/删除二叉搜索树中的节点-450.js

@@ -0,0 +1,52 @@
+let deleteNode = function (root, key) {
+  let findNodePos = (node, key) => {
+    if (!node) {
+      return false
+    }
+    if (node.left && node.left.val === key) {
+      return {
+        parent: node,
+        pos: "left",
+      }
+    } else if (node.right && node.right.val === key) {
+      return {
+        parent: node,
+        pos: "right",
+      }
+    } else {
+      return findNodePos(node.left, key) || findNodePos(node.right, key)
+    }
+  }
+
+  let findLastLeft = (node) => {
+    if (!node.left) {
+      return node
+    }
+    return findLastLeft(node.left)
+  }
+
+  let virtual = new TreeNode()
+  virtual.left = root
+
+  let finded = findNodePos(virtual, key)
+  if (finded) {
+    let { parent, pos } = finded
+    let target = parent[pos]
+    let targetLeft = target.left
+    let targetRight = target.right
+
+    if (!targetLeft && !targetRight) {
+      parent[pos] = null
+    } else if (!targetRight) {
+      parent[pos] = targetLeft
+    } else if (!targetLeft) {
+      parent[pos] = targetRight
+    } else {
+      parent[pos] = targetRight
+      let lastLeft = findLastLeft(targetRight)
+      lastLeft.left = targetLeft
+    }
+  }
+
+  return virtual.left
+}