Add solution #59

Author: JoshCrozier

README.md

@@ -59,6 +59,7 @@
 54|[Spiral Matrix](./0054-spiral-matrix.js)|Medium|
 57|[Insert Interval](./0057-insert-interval.js)|Medium|
 58|[Length of Last Word](./0058-length-of-last-word.js)|Easy|
+59|[Spiral Matrix II](./0059-spiral-matrix-ii.js)|Medium|
 62|[Unique Paths](./0062-unique-paths.js)|Medium|
 66|[Plus One](./0066-plus-one.js)|Easy|
 67|[Add Binary](./0067-add-binary.js)|Easy|

solutions/0059-spiral-matrix-ii.js

@@ -0,0 +1,44 @@
+/**
+ * 59. Spiral Matrix II
+ * https://leetcode.com/problems/spiral-matrix-ii/
+ * Difficulty: Medium
+ *
+ * Given a positive integer n, generate an n x n matrix filled with
+ * elements from 1 to n2 in spiral order.
+ */
+
+/**
+ * @param {number} n
+ * @return {number[][]}
+ */
+var generateMatrix = function(n) {
+  const result = Array.from(new Array(n), () => new Array(n).fill(0));
+  let top = 0;
+  let right = n - 1;
+  let bottom = n - 1;
+  let left = 0;
+
+  for (let count = 0; count < (n * n);) {
+    for (let i = left; i <= right; i++) {
+      result[top][i] = ++count;
+    }
+    top++;
+
+    for (let i = top; i <= bottom; i++) {
+      result[i][right] = ++count;
+    }
+    right--;
+
+    for (let i = right; top <= bottom && i >= left; i--) {
+      result[bottom][i] = ++count;
+    }
+    bottom--;
+
+    for (let i = bottom; left <= right && i >= top; i--) {
+      result[i][left] = ++count;
+    }
+    left++;
+  }
+
+  return result;
+};