C language (Write an alternative version of squeeze(s1,s2) that deletes each character in s1 that matches any character in the string s2)

char is Int

#import 
#include 
#include 
#define N 40

void fun(char s[],int c)
{
 int i=0;
 char*p;
 p=s;
 while(*p)
 {
  if(*p!=c)
  {
   s[i]=*p;
   i++;
  }
  p++;
 }
 s[i]='\0';
}

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    // insert code here...
    
 char stra[N],strb[N];
 int i;
 
 printf("请输入原始字符串a: ");
 gets(stra);
 printf("请输入删除字符串b: ");
 gets(strb);
 
 for(i=0;strb[i]!='\0';i++)
  fun(stra,strb[i]);
 printf("删除指定字符串b后的字符串a: ");
 puts(stra);
 
    [pool drain];
    return 0;
}