chore: import upstream snapshot with attribution

sorting/odd_even_sort.cpp

@@ -0,0 +1,53 @@
+/* C++ implementation Odd Even Sort */
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void oddEven(vector<int> &arr, int size) {
+    bool sorted = false;
+    while (!sorted) {
+        sorted = true;
+        for (int i = 1; i < size - 1; i += 2)  // Odd
+        {
+            if (arr[i] > arr[i + 1]) {
+                swap(arr[i], arr[i + 1]);
+                sorted = false;
+            }
+        }
+
+        for (int i = 0; i < size - 1; i += 2)  // Even
+        {
+            if (arr[i] > arr[i + 1]) {
+                swap(arr[i], arr[i + 1]);
+                sorted = false;
+            }
+        }
+    }
+}
+
+void show(vector<int> A, int size) {
+    int i;
+    for (i = 0; i < size; i++) cout << A[i] << "\n";
+}
+
+int main() {
+    int size, temp;
+    cout << "\nEnter the number of elements : ";
+    cin >> size;
+
+    vector<int> arr;
+
+    cout << "\nEnter the unsorted elements : \n";
+
+    for (int i = 0; i < size; ++i) {
+        cin >> temp;
+        arr.push_back(temp);
+    }
+
+    oddEven(arr, size);
+
+    cout << "Sorted array\n";
+    show(arr, size);
+    return 0;
+}