closeLampInTree

Author: masx200

KnLfVT/index.ts

@@ -1,15 +1,15 @@
-import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
-
-export default function expandBinaryTree(
-    root: TreeNode | null,
-): TreeNode | null {
-    return root
-        ? new TreeNode(
-            root.val,
-            root.left ? new TreeNode(-1, expandBinaryTree(root.left)) : null,
-            root.right
-                ? new TreeNode(-1, null, expandBinaryTree(root.right))
-                : null,
-        )
-        : null;
-}
+import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
+
+export default function expandBinaryTree(
+    root: TreeNode | null,
+): TreeNode | null {
+    return root
+        ? new TreeNode(
+            root.val,
+            root.left ? new TreeNode(-1, expandBinaryTree(root.left)) : null,
+            root.right
+                ? new TreeNode(-1, null, expandBinaryTree(root.right))
+                : null,
+        )
+        : null;
+}

README.md

@@ -45,6 +45,8 @@ Step 2. Add the dependency
 
 <summary>展开查看</summary>
 
+https://leetcode.cn/problems/U7WvvU/
+
 https://leetcode.cn/problems/KnLfVT/
 
 https://leetcode.cn/problems/letter-case-permutation/

U7WvvU/index.ts

@@ -0,0 +1,101 @@
+import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
+
+export default function closeLampInTree(root: TreeNode | null): number {
+    function dfs(root: TreeNode | null) {
+        if (!root) return [0, 0, 0, 0]; // 空节点不需要操作
+
+        const [lAllOpen, lAllClose, lJustSelf, lJustNotSelf] = dfs(root.left);
+        const [rAllOpen, rAllClose, rJustSelf, rJustNotSelf] = dfs(root.right);
+
+        const open = lAllOpen + rAllOpen;
+        const close = lAllClose + rAllClose;
+        const self = lJustSelf + rJustSelf;
+        const notSelf = lJustNotSelf + rJustNotSelf;
+
+        let allOpen = Infinity;
+        let allClose = Infinity;
+        let justSelf = Infinity;
+        let justNotSelf = Infinity;
+
+        // 想达到全开
+        if (root.val) {
+            // 若当前灯开
+            // 左右全开
+            allOpen = Math.min(allOpen, open, close + 2, self + 2, notSelf + 2);
+        } else {
+            // 若当前灯关
+            allOpen = Math.min(
+                allOpen,
+                open + 1,
+                close + 1,
+                self + 3,
+                notSelf + 1,
+            );
+        }
+
+        // 想达到全关
+        if (root.val) {
+            // 灯自己开着
+            allClose = Math.min(
+                allClose,
+                open + 1,
+                close + 1,
+                self + 1,
+                notSelf + 3,
+            );
+        } else {
+            allClose = Math.min(
+                allClose,
+                open + 2,
+                close,
+                self + 2,
+                notSelf + 2,
+            );
+        }
+
+        // 达到只有头开着
+        if (root.val) {
+            justSelf = Math.min(
+                justSelf,
+                open + 2,
+                close,
+                self + 2,
+                notSelf + 2,
+            );
+        } else {
+            // 关着
+            justSelf = Math.min(
+                justSelf,
+                open + 1,
+                close + 1,
+                self + 1,
+                notSelf + 3,
+            );
+        }
+
+        // 达到只有头关着
+        if (root.val) {
+            // 头开着
+            justNotSelf = Math.min(
+                justNotSelf,
+                open + 1,
+                close + 1,
+                self + 3,
+                notSelf + 1,
+            );
+        } else {
+            justNotSelf = Math.min(
+                justNotSelf,
+                open,
+                close + 2,
+                self + 2,
+                notSelf + 2,
+            );
+        }
+
+        return [allOpen, allClose, justSelf, justNotSelf];
+    }
+
+    const [, allClose] = dfs(root);
+    return allClose;
+}