Add passing cars (Go/Java)

Go/jobspls/algorithms/passing_cars.go

@@ -0,0 +1,17 @@
+package algorithms
+
+func PassingCars(cars []int) int {
+	west := 0
+	total := 0
+
+	for _, car := range cars {
+		switch car {
+		case 0:
+			west += 1
+		case 1:
+			total += west
+		}
+	}
+
+	return total
+}

Java/jobspls/algorithms/PassingCars.java

@@ -0,0 +1,19 @@
+package jobspls.algorithms;
+
+public class PassingCars {
+    public static int passing_cars(int[] cars) {
+        var west = 0;
+        var total = 0;
+
+        for (var car : cars) {
+            if (car == 0) {
+                west++;
+            } else {
+                // One eastbound car will pass `west` westbound cars
+                total += west;
+            }
+        }
+
+        return total;
+    }
+}