Create 1359-count-all-valid-pickup-and-delivery-options.java

Author: sujal-goswami

java/1359-count-all-valid-pickup-and-delivery-options.java

@@ -0,0 +1,14 @@
+class Solution {
+    public int countOrders(int n) {
+        int MOD = (int) 1e9 + 7;
+        int slots = 2*n;
+        long res = 1;
+
+        while(slots > 0){
+            int valid_choices = slots*(slots - 1)/2;
+            res = (res * valid_choices) % MOD;
+            slots -= 2;
+        }
+        return (int)res;
+    }
+}