427/js

Author: zheeeng

427.construct-quad-tree.0.js

@@ -0,0 +1,37 @@
+/*
+ * @lc app=leetcode id=427 lang=javascript
+ *
+ * [427] Construct Quad Tree
+ */
+/**
+ * // Definition for a QuadTree node.
+ * function Node(val,isLeaf,topLeft,topRight,bottomLeft,bottomRight) {
+ *    this.val = val;
+ *    this.isLeaf = isLeaf;
+ *    this.topLeft = topLeft;
+ *    this.topRight = topRight;
+ *    this.bottomLeft = bottomLeft;
+ *    this.bottomRight = bottomRight;
+ * };
+ */
+/**
+ * @param {number[][]} grid
+ * @return {Node}
+ */
+const construct = function(grid) {
+  const len = grid.length
+
+  if (len == 1) {
+    return new Node(grid[0][0] == 1 ? true : false, true)
+  } else {
+    const g1 = construct(grid.slice(0, len / 2).map(it => it.slice(0, len / 2)))
+    const g2 = construct(grid.slice(0, len / 2).map(it => it.slice(len / 2)))
+    const g3 = construct(grid.slice(len / 2).map(it => it.slice(0, len / 2)))
+    const g4 = construct(grid.slice(len / 2).map(it => it.slice(len / 2)))
+
+    const isLeaf = g1.isLeaf && g2.isLeaf && g3.isLeaf && g4.isLeaf
+    const isSame = g1.val == g2.val && g2.val == g3.val && g3.val == g4.val
+
+    return (isLeaf && isSame) ? new Node(g1.val, true) : new Node(false, false, g1, g2, g3, g4)
+  }
+}