Create SortAnArray.cpp

Author: sudoshivesh

medium/SortAnArray.cpp

@@ -0,0 +1,42 @@
+//912. Sort an Array
+class Solution {
+ public:
+  vector<int> sortArray(vector<int>& nums) {
+    mergeSort(nums, 0, nums.size() - 1);
+    return nums;
+  }
+
+ private:
+  void mergeSort(vector<int>& A, int l, int r) {
+    if (l >= r)
+      return;
+
+    const int m = (l + r) / 2;
+    mergeSort(A, l, m);
+    mergeSort(A, m + 1, r);
+    merge(A, l, m, r);
+  }
+
+  void merge(vector<int>& A, int l, int m, int r) {
+    vector<int> sorted(r - l + 1);
+    int k = 0;      // sorted's index
+    int i = l;      // left's index
+    int j = m + 1;  // right's index
+
+    while (i <= m && j <= r)
+      if (A[i] < A[j])
+        sorted[k++] = A[i++];
+      else
+        sorted[k++] = A[j++];
+
+    // Put possible remaining left part to the sorted array
+    while (i <= m)
+      sorted[k++] = A[i++];
+
+    // Put possible remaining right part to the sorted array
+    while (j <= r)
+      sorted[k++] = A[j++];
+
+    copy(begin(sorted), end(sorted), begin(A) + l);
+  }
+};