#include <stdio.h>
#include <time.h>

#define UNIT	(30*60)
#define FEE	300

time_t  get_caltime(char *tstr);

main()
{
	time_t  cal_stime, cal_etime;
	char    buff[100];
	int	fee, unit;

	printf("駐車開始時間 YYYYMMDDHHMMSS : ");
	scanf("%s", buff);
	cal_stime = get_caltime(buff);
	if(cal_stime == -1){
		printf("変換失敗\n");
		return;
	}
	printf("駐車終了時間 YYYYMMDDHHMMSS : ");
	scanf("%s", buff);
	cal_etime = get_caltime(buff);
	if(cal_etime == -1){
		printf("変換失敗\n");
		return;
	}

	if(cal_etime <= cal_stime){
		printf("入力した日時が不適切です.\n");
		return;
	}
	printf("経過秒数 : %d\n", cal_etime - cal_stime);        
	unit = (cal_etime - cal_stime) / UNIT;
	if((cal_etime - cal_stime) % UNIT != 0)
		unit++;
	fee = unit * FEE;
	printf("料金 : %d円\n", fee);
}


time_t  get_caltime(char *tstr)
{
	char    buf[20];
	time_t  cal_time;
	struct tm
		work_tm;

	if(strlen(tstr) != 14)
		return(-1);
	strncpy(buf, tstr, 4);
	buf[4] = '\0';
	work_tm.tm_year = atoi(buf) - 1900;
	strncpy(buf, tstr+4, 2);
	buf[2] = '\0';
	work_tm.tm_mon = atoi(buf) - 1;
	strncpy(buf, tstr+4+2, 2);
	work_tm.tm_mday = atoi(buf);
	strncpy(buf, tstr+4+2+2, 2);
	work_tm.tm_hour = atoi(buf);
	strncpy(buf, tstr+4+2+2+2, 2);
	work_tm.tm_min = atoi(buf);
	strncpy(buf, tstr+4+2+2+2+2, 2);
	work_tm.tm_sec = atoi(buf);
	work_tm.tm_isdst = -1;
	if((cal_time = mktime(&work_tm)) == -1){
		return(-1);
	}
	return(cal_time);
}