https://leetcode.cn/problems/binary-tree-cameras

Author: shixuan.ma

README.md

@@ -152,6 +152,8 @@ go get github.com/masx200/leetcode-test
 
 <summary>展开查看</summary>
 
+https://leetcode.cn/problems/binary-tree-cameras
+
 https://leetcode.cn/problems/snail-traversal/
 
 https://leetcode.cn/problems/function-composition

binary-tree-cameras/index.ts

@@ -0,0 +1,18 @@
+import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
+
+function minCameraCover(root: TreeNode | null): number {
+    const dfs = (root: TreeNode | null): [number, number, number] => {
+        if (!root) {
+            return [Math.floor(Number.MAX_SAFE_INTEGER / 2), 0, 0];
+        }
+        const [la, lb, lc] = dfs(root.left);
+        const [ra, rb, rc] = dfs(root.right);
+        const a = lc + rc + 1;
+        const b = Math.min(a, Math.min(la + rb, ra + lb));
+        const c = Math.min(a, lb + rb);
+        return [a, b, c];
+    };
+
+    return dfs(root)[1];
+}
+export default minCameraCover;