Purpose: Learn how to use the pointers to represent strings in C. Part 1: Write a function about string copy, the strcpy prototype "char* strepy (char* strDest, const char strSrc)". Here strDest is destination string, strSrc is source string. 1) Write the function strcpy, don't call C string library. 2) Here strcpy can copy strSrc to strDest, but why we use char* as the return value of strcpy