Code C++

#include <iostream>
#include <string>
using namespace std;

string ArrayToString(int* array, int arraySize) {
   // Special case for empty array
   if (0 == arraySize) {
      return string("[]");
   }
   
   // Start the string with the opening '[' and element 0
   string result = "[" + to_string(array[0]);
   
   // For each remaining element, append comma, space, and element
   for (int i = 1; i < arraySize; i++) {
      result += ", ";
      result += to_string(array[i]);
   }
   
   // Add closing ']' and return result
   result += "]";
   return result;
}

int InsertionSortInterleaved(int* numbers, int numbersSize, int startIndex, int gap) {
   int swaps = 0;
   for (int i = startIndex + gap; i < numbersSize; i += gap) {
      int j = i;
      while (j - gap >= startIndex && numbers[j] < numbers[j - gap]) {
         swaps++;
         // Swap numbers[j] and numbers [j - 1]
         int temp = numbers[j];
         numbers[j] = numbers[j - gap];
         numbers[j - gap] = temp;
         j -= gap;
      }
   }
   return swaps;
}
   
int ShellSort(int* numbers, int numbersSize, int* gapValues, int gapValuesSize) {
   int totalSwaps = 0;
   for (int g = 0; g < gapValuesSize; g++) {
      int swapsForGap = 0;
      for (int i = 0; i < gapValues[g]; i++) {
         swapsForGap += InsertionSortInterleaved(numbers, numbersSize, i, gapValues[g]);
      }
      cout << ArrayToString(numbers, numbersSize) << " (after " << swapsForGap;
      cout << " swap" << (swapsForGap == 1 ? "" : "s") << " with gap=";
      cout << gapValues[g] << ")" << endl;
      totalSwaps += swapsForGap;
   }
   return totalSwaps;
}

int main() {
   // Create an array of numbers to sort
   int numbers[] =     { 55, 99, 87, 54, 31, 17, 28, 18 };
   int numbersCopy[] = { 55, 99, 87, 54, 31, 17, 28, 18 };
   int numbersSize = sizeof(numbers) / sizeof(numbers[0]);
      
   // Display the contents of the array
   cout << "---- Shell sort ----" << endl;
   cout << "UNSORTED: " << ArrayToString(numbers, numbersSize) << endl;
      
   // Call the ShellSort function
   int gapValues[] = { 4, 2, 1 };
   int gapValuesSize = sizeof(gapValues) / sizeof(gapValues[0]);
   int totalSwaps = ShellSort(numbers, numbersSize, gapValues, gapValuesSize);

   // Display sorted array and the total number of swaps
   cout << "SORTED:   " << ArrayToString(numbers, numbersSize) << endl;
   cout << "Total swaps: " << totalSwaps << endl;
      
   // Sort the same array with insertion sort
   cout << endl << "---- Regular insertion sort ----" << endl;
   cout << "UNSORTED: " << ArrayToString(numbersCopy, numbersSize) << endl;
   totalSwaps = InsertionSortInterleaved(numbersCopy, numbersSize, 0, 1);
   cout << "SORTED:   " << ArrayToString(numbersCopy, numbersSize) << endl;
   cout << "Total swaps: " << totalSwaps << endl;
}