150. Function Pointer apply

 You are given two functions already defined:

int square(int x) { return x * x; }
int cube(int x) { return x * x * x; }

In main(), these functions are already called using a function pointer.

Your task is to write the function:

void apply(int x, int (*op)(int))

• It should call op(x) and print the result. 

Example:

Example 1
 Input:

5 square

Output:

25

Example 2

Input:

3 cube

Output:

27