K-diff Pairs in an Array (C++) (#62)

* K-diff pairs in an array (C++) added

* K-diff pairs in an array (C++) Added

Author: tanmay-j1

C++/k-diff-pairs-in-an-array.cpp

@@ -0,0 +1,28 @@
+// A simple cpp solution using maps and set 
+
+class Solution {
+public:
+    int findPairs(vector<int>& nums, int k) {
+        
+        map<int,int> m;
+        set<pair<int,int>> sp;
+        
+        // create a map storing all the frequencies
+        for(int i:nums) m[i]++;
+        
+        int ans=0;
+        for(auto i:m){
+
+            // if k = 0, add one entry to the set if freq > 1
+            if(k==0 && m[i.first]>1){
+                sp.insert({i.first,i.first});
+            }
+            else if(k!=0 && m.find(i.first+k)!=m.end()){
+                sp.insert({i.first,i.second});
+            }
+        }
+
+        // answer is the number of elements in the set
+        return sp.size();
+    }
+};

README.md

@@ -103,6 +103,7 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 | 495 | [Teemo Attacking](https://leetcode.com/problems/teemo-attacking)       | [C++](./C++/teemo-attacking.cpp)    | _O(n)_     | _O(1)_ | Medium| Array |    |
 | 15 | [3 Sum](https://leetcode.com/problems/3sum/) | [Python](./Python/ThreeNumbersSum.py) | O( nLog(n) ) | O(1) | Medium | Array |
 | 1200 | [Minimum Absolute Difference](https://leetcode.com/problems/minimum-absolute-difference/) | [Python](./python/SmallestDifference.py) | O(n) | O(1) | Easy | Array | 
+| 532 | [K-diff Pairs in an Array](https://leetcode.com/problems/k-diff-pairs-in-an-array/) | [C++](./C++/k-diff-pairs-in-an-array.cpp) | O(n) | O(n) | Medium | Array | 
 
 
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