Sync LeetCode submission - Number of Ways to Divide a Long Corridor (…

…javascript)

problems/number_of_ways_to_divide_a_long_corridor/solution.js

@@ -0,0 +1,23 @@
+/**
+ * @param {string} corridor
+ * @return {number}
+ */
+// Dynamic programming
+var numberOfWays = function(corridor) {
+    // a the number of 0 seat
+    // b the number of 1 seat
+    // c the number of 2 seats
+    let a = 1, b = 0, c = 0, mod = 1e9 + 7;
+
+    for (let i = 0; i < corridor.length; ++i) {
+        a = (a + c) % mod;
+
+        if (corridor.charAt(i) === 'S') {    
+            c = b;
+            b = a;
+            a = 0;
+        }
+    }
+
+    return c;
+};