PAT 1050. String Subtraction (20)

#include<cstdio>#include<cstdlib>#include<cstring>#include<iostream>#include<vector>#include<queue>#include<algorithm>using namespace std;#define maxsize 10001#define  MIN -10001int main(){    char s1[maxsize],s2[maxsize];    gets(s1);    gets(s2);    for(int i=0;s1[i]!='\0';i++)        if(strchr(s2,s1[i])==NULL)          printf("%c",s1[i]);    printf("\n");    return 0;}