Day3 Coding Interview || k-diff-pairs-in-an-array

Easy

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;
+    }
+};