C++ question

You are NOT allowed to use any kind of loops in any part of your submitted code. You are NOT allowed to use goto. You are NOT allowed to use any global variable, or static variable like static int x. You are NOT allowed to include any additional libraries (e.g. cstring library or cmath library) yourself. Everything you need is already included. However, feel free to implement any functions you need yourself with recursion. You are NOT allowed to modify any of the given function prototypes including the return types, function names, and parameter lists. (but you can overload them if you want we will explain why you might want to do that later) int evaluate(const char str) This function returns the integer result of a given formula stored in the non-empty C-string str. You can assume the given string always represents a valid formula which is defined as a formula that can be printed by the given printArray function. Examples: . If str is "1+1", the function should return 2. . If str is "-2", the function should return -2. . If str is "123-456", the function should return -333. . If str is "123-456+8-9+2", the function should return -332. Hint: While you cannot use any function from the cstring library or any other libraries, you can implement the "strlen" function with recursion yourself for this task if needed