Add solution #62

Author: JoshCrozier

README.md

@@ -54,6 +54,7 @@
 53|[Maximum Subarray](./0053-maximum-subarray.js)|Easy|
 54|[Spiral Matrix](./0054-spiral-matrix.js)|Medium|
 58|[Length of Last Word](./0058-length-of-last-word.js)|Easy|
+62|[Unique Paths](./0062-unique-paths.js)|Medium|
 66|[Plus One](./0066-plus-one.js)|Easy|
 67|[Add Binary](./0067-add-binary.js)|Easy|
 69|[Sqrt(x)](./0069-sqrtx.js)|Medium|

solutions/0062-unique-paths.js

@@ -0,0 +1,34 @@
+/**
+ * 62. Unique Paths
+ * https://leetcode.com/problems/unique-paths/
+ * Difficulty: Medium
+ *
+ * There is a robot on an m x n grid. The robot is initially located at the top-left
+ * corner (i.e., grid[0][0]). The robot tries to move to the bottom-right corner
+ * (i.e., grid[m - 1][n - 1]). The robot can only move either down or right at any
+ * point in time.
+ *
+ * Given the two integers m and n, return the number of possible unique paths that
+ * the robot can take to reach the bottom-right corner.
+ */
+
+/**
+ * @param {number} m
+ * @param {number} n
+ * @return {number}
+ */
+var uniquePaths = function(m, n) {
+  const row = new Array(n);
+
+  for (let i = 0; i < n; i++) {
+    row[i] = 1;
+  }
+
+  for (let i = 1; i < m; i++) {
+    for (let j = 1; j < n; j++) {
+      row[j] += row[j - 1];
+    }
+  }
+
+  return row[n - 1];
+};