I know I should be using vectors, but I want to get better at dynamically allocating arrays. I’m not sure where I went wrong. I’m creating a new array and deleting it.

void Merge(int *arr,int begin, int mid, int end){

    int*arrB = new int[mid - begin + 1];
    int i = begin;
    int j = mid+1;
    int k = 0;
    
    
    
    while(i <= mid && j <= end){
        if(arr[i] <= arr[j]){
            arrB[k] = arr[i];
            k++;
            i++;
        }
        else {
            arrB[k] = arr[j];
            k++;
            j++;
        }

    }
    
    while(i <= mid){
        arrB[k] = arr[i];
        i++;
        k++;
    }
    while(j <= end){
        arrB[k] = arr[j];
        j++;
        k++;
    }
    
    k = 0;
    for(int i = begin; i <= end; i++){
        arr[i] = arrB[k];
        s.setData(arr);
        k++;
    }
    
    
        delete[] arrB; //error here
}

I’ve tried replacing <= to < for n-1, I’ve tried switching to vectors and that also gives me an error. I’ve also tried looking at similar questions.

>Solution :

void Merge(int *arr, int begin, int mid, int end) {
  // Allocate the arrB array on the stack instead of the heap
  int arrB[mid - begin + 1];



 int i = begin;
  int j = mid+1;
  int k = 0;



 // Initialize the k variable to 0 before using it to index arrB
  k = 0;



 while (i <= mid && j <= end) {
    if (arr[i] <= arr[j]) {
      arrB[k] = arr[i];
      i++;
    } else {
      arrB[k] = arr[j];
      j++;
    }



   // Increment the k variable after each element is added to arrB
    k++;
  }



 while (i <= mid) {
    arrB[k] = arr[i];
    i++;
    k++;
  }
  while (j <= end) {
    arrB[k] = arr[j];
    j++;
    k++;
  }



 // Call the setData method once, outside of the for loop
  s.setData(arr);



 k = 0;
  for (int i = begin; i <= end; i++) {
    arr[i] = arrB[k];
    k++;
  }
}