Create 655-print-binary-tree.js

Author: everthis

655-print-binary-tree.js

@@ -0,0 +1,29 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {string[][]}
+ */
+const printTree = function (root) {
+  const h = getH(root)
+  const w = Math.pow(2, h) - 1
+  const matrix = new Array(h).fill(0).map((_) => new Array(w).fill(''))
+  fill(root, 0, 0, w - 1)
+  return matrix
+  function getH(root) {
+    if (!root) return 0
+    return Math.max(getH(root.left), getH(root.right)) + 1
+  }
+  function fill(root, level, start, end) {
+    if (!root) return
+    let mid = (start + end) / 2
+    matrix[level][mid] = root.val + ''
+    fill(root.left, level + 1, start, mid - 1)
+    fill(root.right, level + 1, mid + 1, end)
+  }
+}