add 62-Unique-Paths

javascript/62-Unique-Paths.js

@@ -0,0 +1,15 @@
+function uniquePaths(m, n) {
+  let row = new Array(n).fill(1);
+
+  for (let i = 0; i < m - 1; i++) {
+    let newRow = new Array(n).fill(1);
+
+    for (let j = n - 2; j > -1; j--) {
+      newRow[j] = newRow[j + 1] + row[j];
+    }
+
+    row = newRow;
+  }
+
+  return row[0];
+}