Create find_original_array_from_doubled_array.cpp

Author: avidLearnerInProgress

find_original_array_from_doubled_array.cpp

@@ -0,0 +1,23 @@
+class Solution {
+public:
+    vector<int> findOriginalArray(vector<int>& changed) {
+        unordered_map<int, int> freq;
+        for (auto num : changed) freq[num]++;
+        
+        sort(changed.begin(), changed.end());
+        
+        vector<int> res;
+        for (auto num : changed) {
+            if (freq[num] && freq[num*2]) {
+                freq[num]--;
+                freq[num*2]--;
+                res.push_back(num);
+            }
+        }
+        
+        for (auto [a, b] : freq)
+            if (b) return {};
+        
+        return res;
+    }
+};