In C++, how to manipulate the elements in an array with pointers

Question

Update the array values from { 5, 10, 15 } to { 30, 20, 10 } using pointers. In the end of the method, print out the elements in the array using pointers as well.

Solution

int main()
{
int arr[3] = { 5, 10, 15 };
int* ptr = arr;
*ptr = 10;          // set arr[0] to 10
*(ptr + 1) = 20;      // set arr[1] to 20