Reverse Pairs Problem - Array

Arrays/reversePairs.cpp

@@ -0,0 +1,32 @@
+/* Problem Statement : Given an integer array nums, 
+return the number of reverse pairs in the array.
+A reverse pair is a pair (i, j) where:
+--> 0 <= i < j < nums.length and
+--> nums[i] > 2 * nums[j]. */
+
+
+#include<bits/stdc++.h>
+using namespace std;
+
+ int reversePairs(vector < int > & arr) {
+      int Pairs = 0;
+      for (int i = 0; i < arr.size(); i++) {
+        for (int j = i + 1; j < arr.size(); j++) {
+          if (arr[i] > 2 * arr[j]) Pairs++;
+        }
+      }
+      return Pairs;
+    }
+
+
+int main()
+{
+    int n;
+    cin>>n;
+    vector<int> arr(n);
+    for(int i=0;i<n;i++){
+      cin>>arr[i];
+    }
+    cout<<reversePairs(arr)<<endl;
+    return 0;
+}