Here's an explanation of each line of the rotate function in more detail:

This line defines the rotate function, which takes a vector of integers nums and an integer k as input, and does not return a value (i.e., it has a void return type). The function will modify the input vector in-place to rotate its elements to the right by k positions.

This line calculates the size of the input vector nums and stores it in the variable n

This line calculates the modulo of k with n to handle the case where k is greater than n. For example, if n is 5 and k is 7, then k is reduced to 2 (i.e., 7 % 5 = 2).

This line checks if k is zero. If it is, then the function immediately returns because rotating the vector by zero positions would result in the vector being unchanged.

This line uses the reverse function from the library to reverse the entire vector nums. This has the effect of reversing the order of all elements in the vector.

This line uses the reverse function again to reverse the first k elements of the vector nums. The expression nums.begin() + k gives the iterator to the element in the vector immediately after the first k elements. So this line effectively reverses the order of the first k elements in the vector.

This line uses reverse one more time to reverse the remaining elements of the vector nums. The expression nums.begin() + k gives the iterator to the element in the vector immediately after the first k elements, so this line effectively reverses the order of the remaining elements in the vector.

Thank you..!