PAT 的一道一元二次方程求导问题，实在想不出来用例 3 怎么一直错误。

#include <stdio.h>
int main()
{
    int base, exp;
    scanf ( "%d %d", &base, &exp );
    if ( exp == 0 )
    {
        printf ( "%d %d", 0, 0 );
    }
    else
    {
        printf ( "%d %d", base*exp, exp-1 );

        while ( exp - 1 != 0 )
        {
            scanf ( "%d %d", &base, &exp );
            printf ( " %d %d", base*exp, exp-1 );

        } 
    }

    return 0;
}

#include <stdio.h>

int main()
{
    int base, exp;
    int flag = 0;

    while ( scanf( "%d %d", &base, &exp ) != EOF )
    {
        if ( base*exp != 0 )
        {
            if ( flag != 0 )
            {
                printf (" ");
            }
            else
            {
                flag = 1;
            }
            printf ( "%d %d", base*exp, exp-1 );
        }
    }

    if ( flag == 0 )
    {
        printf ( "%d %d", 0, 0 );
    }

    return 0;
}