C# writing a function by reference.

Hello Guys, Thank you very much for your prompt replies. Actually I want to write a function as follows:

Write a function:

int symmetryPoint(char *S);

that, given a string S, returns the index (counting from 0) of a character such that the part of the string to the left of that character is a reversal of the part of the string to its right. The function should return -1 if no such index exists.

Note: reversing an empty string (i.e. a string whose length is zero) gives an empty string.

For example, given a string:

"racecar"

the function should return 3, because the substring to the left of the character "e" at index 3 is "rac", and the one to the right is "car".

Given a string:

"x"

the function should return 0, because both substrings are empty.

Assume that:

·    the length of S is within the range [0..2,000,000].

Complexity:

 

·    expected worst-case time complexity is O(length(S));

·    expected worst-case space complexity is O(1) (not counting the storage required for input arguments).