/*
 * Program to convert Julian date to month/day format.
 */
#include <stdio.h>

#define JAN 31
#define FEB 28
#define MAR 31
#define APR 30
#define MAY 31
#define JUN 30
#define JUL 31
#define AUG 31
#define SEP 30
#define OCT 31
#define NOV 30
#define DEC 31

int main(void) {

    int days_per_month[] = { 
        JAN, FEB, MAR, APR, MAY, JUN,
        JUL, AUG, SEP, OCT, NOV, DEC
    };

    int jdate;

    printf("enter julian date\n");
    if (scanf("%d", &jdate) != 1) {
        printf("error -- non-numeric input\n"); return 1;
    }
    else if ((jdate < 1) || (jdate > 365)) {
            printf("error -- out of range (1 .. 365)\n"); return 1;
    }

    int month = 0;
    int days_left = jdate;

    while (days_left > days_per_month[month]) {
        days_left -= days_per_month[month];
        month += 1;
    }
    month += 1;

    printf("julian date %d is %d/%02d\n", jdate, month, days_left);
    return 0;
}