Merge pull request #85 from walkoverr/main

create pairs with difference k

cpp/Pairs with difference k.cpp

@@ -0,0 +1,41 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+public:
+    int countPairsWithDiffK(vector<int>& arr, int k) {
+        unordered_map<int, int> elementCount;
+        int count = 0;
+
+        // Populate the map with frequencies of each element.
+        for (int num : arr) {
+            elementCount[num]++;
+        }
+
+        // Iterate through each unique element in the map.
+        for (const auto& element : elementCount) {
+            int value = element.first;
+
+            // If `value + k` exists in the map, add to count.
+            if (elementCount.find(value + k) != elementCount.end()) {
+                count += element.second * elementCount[value + k];
+            }
+        }
+        return count;
+    }
+};
+
+int main() {
+    Solution solution;
+    vector<int> arr1 = {1, 5, 3, 4, 2};
+    int k1 = 3;
+    cout << "Number of pairs with difference " << k1 << ": " 
+              << solution.countPairsWithDiffK(arr1, k1) << endl;
+
+    vector<int> arr2 = {8, 12, 16, 4, 0, 20};
+    int k2 = 4;
+    cout << "Number of pairs with difference " << k2 << ": " 
+              << solution.countPairsWithDiffK(arr2, k2) <<endl;
+
+    return 0;
+}