From b7249672198739862806804c117f30b2443fdfe1 Mon Sep 17 00:00:00 2001
From: Rachit Jain <32428330+rachitiitr@users.noreply.github.com>
Date: Sun, 4 Oct 2020 13:33:53 +0530
Subject: [PATCH] Day3 Coding Interview || k-diff-pairs-in-an-array

Easy
---
 LeetCode/532.k-diff-pairs-in-an-array.cpp | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 LeetCode/532.k-diff-pairs-in-an-array.cpp

diff --git a/LeetCode/532.k-diff-pairs-in-an-array.cpp b/LeetCode/532.k-diff-pairs-in-an-array.cpp
new file mode 100644
index 0000000..eda9324
--- /dev/null
+++ b/LeetCode/532.k-diff-pairs-in-an-array.cpp
@@ -0,0 +1,21 @@
+using hashmap = unordered_map<int, int>;
+
+class Solution {
+public:
+    int findPairs(vector<int>& nums, int k) {
+        hashmap cnt;
+        for(int x: nums) cnt[x]++;
+        
+        int ans = 0;
+        for(auto p: cnt) { // iterating on unique numbers of the array 
+            int x = p.first;
+            // check x+k exists in the array
+            if(cnt.find(x+k) == cnt.end()) {
+                continue;
+            }
+            ans += (k==0) ? cnt[x+k] >= 2 : cnt[x+k] >= 1;
+        }
+        
+        return ans;
+    }
+};