字符串合并问题

#include <stdio.h>
#include <string.h>
void hzfc(char *Path,char *Pah);//改成void hzfc(char []Path,char []Pah);报错
void hzfc(char *Path,char *Pah) {
char *d="\\";/改成[]报错
strcat(Path,d);
strcat(Path,Pah);
printf("%s\n",Path);
}
int main()
{
hzfc("123","456.txt");
}