Add C++ solution of problem #2558

Author: Cuda-Chen

2558/solution.cpp

@@ -0,0 +1,19 @@
+class Solution {
+public:
+    long long pickGifts(vector<int>& A, int k) {
+        priority_queue<int> q(begin(A), end(A));
+        for(int i = 0; i < k; i++) {
+            int tmp = q.top();
+            q.pop();
+            tmp = sqrt(tmp);
+            q.push(tmp);
+        }
+
+        long long ans = 0LL;
+        while(!q.empty()) {
+            ans += q.top();
+            q.pop();
+        }
+        return ans;
+    }
+};