Improvement: use smart pointer for RAII i.e. Scope-Bound Memory Management

3_squares_of_a_sorted_array.cpp

@@ -2,6 +2,7 @@
  */
 
 #include <iostream>
+#include <memory>
 #include <vector>
 
 template <typename T> inline T absolute(T num) {
@@ -11,9 +12,9 @@ template <typename T> inline T absolute(T num) {
 template <typename T> inline T square(T num) { return num * num; }
 
 template <typename T>
-std::vector<T> &solution(const std::vector<T> &sorted_input) {
+std::unique_ptr<std::vector<T>> solution(const std::vector<T> &sorted_input) {
-  std::vector<T> *result = new std::vector<T>(sorted_input.size());
+  std::unique_ptr<std::vector<T>> sorted_output =
-  std::vector<T> &sorted_output = *result;
+      std::make_unique<std::vector<T>>(sorted_input.size());
   unsigned long long p1 = 0, p2 = 1;
   while (p2 < sorted_input.size()) {
     if (absolute(sorted_input[p2]) <= absolute(sorted_input[p1]))
@@ -27,21 +28,21 @@ std::vector<T> &solution(const std::vector<T> &sorted_input) {
   unsigned long long output_p = 0;
   while (p1 < p2 && p2 < sorted_input.size()) {
     if (absolute(sorted_input[p1]) < absolute(sorted_input[p2]))
-      sorted_output[output_p++] = (square(sorted_input[p1--]));
+      (*sorted_output)[output_p++] = (square(sorted_input[p1--]));
     else
-      sorted_output[output_p++] = square(sorted_input[p2++]);
+      (*sorted_output)[output_p++] = square(sorted_input[p2++]);
   }
   while (p1 < p2)
-    sorted_output[output_p++] = square(sorted_input[p1--]);
+    (*sorted_output)[output_p++] = square(sorted_input[p1--]);
   while (p2 < sorted_input.size())
-    sorted_output[output_p++] = square(sorted_input[p2++]);
+    (*sorted_output)[output_p++] = square(sorted_input[p2++]);
   return sorted_output;
 }
 
 int main() {
-  std::vector<int> &result = solution(std::vector{-4, -1, 0, 3, 10});
+  std::unique_ptr<std::vector<int>> result =
-  for (const int num : result)
+      solution(std::vector{-4, -1, 0, 3, 10});
+  for (const int num : *result)
     std::cout << num << ", ";
   std::cout << std::endl;
-  delete &result;
 }