c语言，回文序列的判断，runtime error 求大神解答

Question

#include
#include
int main(){
int i,*pi,l,*pl,mark,*pmark;
pi=&i;
pl=&l;
pmark=&mark;
char str[100000],*pstr;
pstr=str;

while((scanf("%s",pstr)!=EOF)&&strcmp（str,"2013"）!=0){
pl=strlen(pstr);
mark=1;
for(*pi=0;*pi<(l/2);*pi++){
if((pstr+i)!=*(pstr+(*pl-*pi-1))){
mark=0;
break;

}
}
if(mark){
printf("YES\n");
}
else{
printf("NO\n");
}
}
return 0;
}

Answer 1

#include
#include
#include
int main() {
int i,*pi,l,*pl,mark,*pmark;
pi=&i;
pl=&l;
pmark=&mark;
char str[100000],*pstr;
pstr=str;

while((scanf("%s",pstr)!=EOF)&&strcmp(str,"2013")!=0) {
    *pl=(int)strlen(pstr);
    mark=1;
    for(*pi=0; *pi<(l/2); *pi++) {
        int temp = (*pl-*pi-1);
        if((pstr+i)!=(pstr+temp)) {
            mark=0;
            break;
        }
    }
    if(mark) {
        printf("YES\n");
    } else {
        printf("NO\n");
    }
}
return 0;

}//这样可以运行，但是逻辑还需要修改