#include <stdio.h>
#include <string.h>
long fun( char *s )
{
int i;
long sum=0;
for(i=0;i<strlen(s);i++){
sum=sum*10+s[i]-'0';
}
return sum;
}
void main()
{ char s[10]; long r;
printf("請輸入一個長度不超過9個字符的數字字符串 : "); gets(s);
r = fun( s );
printf(" r = %ld\n" , r );
}