Huawei machine questions-string operations

/* Problem description: & nbsp; remove all other characters in a string except uppercase letters, lowercase letters, and numbers, and output a new string. & Nbsp; required implementation functions: & nbsp; void & nbsp; my_string (char * & nbsp; input, & nbsp; char * & nbsp; output) & nbsp; [input] & nbsp; char * & nbsp; input, input string & nbsp; [output] & nbsp; char * & nbsp; output, & nbsp; Output string & nbsp; [Return] & nbsp; none & nbsp; example & nbsp; input: input & nbsp; = & nbsp; "A * (BC & De + _ fg/*" & nbsp; output: output & nbsp ;=& nbsp; "ABCDefg" & nbsp; input: input & nbsp; = & nbsp; "AB + _ 9" & nbsp; output: output & nbsp; = & nbsp; "aB9" */# include <iostream> using namespa Ce std; void my_string (char * input, char * output) {int I; int j; j = 0; for (I = 0; input [I]! = '\ 0'; I ++) if (isalnum (input [I])! = 0) output [j ++] = input [I]; output [j] = '\ 0';} int main (void) {char * input = "A * (BC & De + _ fg/*"; char * output = new char [100]; my_string (input, output ); cout <output <endl; input = "AB + _ 9"; my_string (input, output); cout <output <endl; system ("pause "); return 0 ;}