Merge branch 'master' of https://github.com/sl1673495/leetcode-javascript

Author: sl1673495

二叉树/二叉搜索树中第K小的元素.js

@@ -0,0 +1,34 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @param {number} k
+ * @return {number}
+ */
+var kthSmallest = function (root, k) {
+  let count = 0
+  let finded
+
+  let dfs = (node) => {
+    if (!node) {
+      return
+    }
+    dfs(node.left)
+    count++
+    if (count === k) {
+      finded = node.val
+      return
+    }
+    dfs(node.right)
+  }
+
+  dfs(root)
+
+  return finded
+}

二叉树/二叉树的最小深度-111.js

@@ -0,0 +1,27 @@
+let minDepth = function (root) {
+  if (!root) return 0
+
+  let depth = 0
+  let queue = [root]
+
+  while (queue.length) {
+    depth++
+    let len = queue.length
+    while (len--) {
+      let node = queue.shift()
+
+      let left = node.left
+      let right = node.right
+      if (!left && !right) {
+        return depth
+      }
+
+      if (left) {
+        queue.push(left)
+      }
+      if (right) {
+        queue.push(right)
+      }
+    }
+  }
+}

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
+}

二叉树/将有序数组转为二叉搜索树.js

@@ -0,0 +1,13 @@
+let sortedArrayToBST = function (nums) {
+  let n = nums.length
+  if (!n) {
+      return null
+  }
+  let mid = Math.floor(n / 2)
+  let root = new TreeNode(nums[mid])
+
+  root.left = sortedArrayToBST(nums.slice(0, mid))
+  root.right = sortedArrayToBST(nums.slice(mid + 1, n))
+
+  return root
+};