《C primer plus》Chapter 14.2

# include <stdio.h>
# define LEN 10
struct date
{
    int year;
    int month;
    int day;
};
int main(void)
{
    struct date data[12]=
    {
        {2018,1,31},
        {2018,2,28},
        {2018,3,31},
        {2018,4,30},
        {2018,5,31},
        {2018,6,30},
        {2018,7,31},
        {2018,8,31},
        {2018,9,30},
        {2018,10,31},
        {2018,11,30},
        {2018,12,31}
    };
    int a,b,c,i,n;

    printf("Please enter a date like 2018-1-1(letter to quit) :\n");
    while(scanf("%d-%d-%d",&a,&b,&c)==3)
    {
        int sum=0;
        for(i=0;i<12;i++)
        {
            if(b==data[i].month)
            {
                if(c<=data[i].day)
                {
                    for(n=0;n<i;n++)
                    {
                        sum+=data[n].day+c;
                    }
                    break;
                }
                else if(c>data[i].day)
                {
                    printf("No this day!\n");
                    break;
                }
            }
        }
        printf("The sum days are %d!\n",sum);
        printf("Please enter a date like 2018 1 1:\n");
    }
    return 0;
}