day calculating.... 3 days fishing,2 days netting.....

fishing.c

#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <ctype.h>
#include <stdbool.h>

const int STARTYEAR   	= 1990,
          STARTMONTH 		= 1,
          STARTDAY 			= 1,
          ENDYEAR 			= 2100;
const int DAYSOFCOMMONYEAR 	= 365;
const int tbl[][13] 		=
{
    {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
    {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
};

inline bool isLeapYear (int year)
{
    return (year % 400 == 0) ||
           (year % 4 == 0 && year % 100 != 0);
}

bool navieQuery (int year, int month, int day)
{
    int i, daysPast = day -1;
    bool isLeap = isLeapYear(year);
    /*
     *count total years,example:
     *1990.01.01 ~ 2012.01.01
     */

    for (i = STARTYEAR; i <= year; ++i)
        daysPast += DAYSOFCOMMONYEAR + isLeapYear(i);

    for (i = 0; i < month; ++i)
        daysPast += tbl[isLeap][i];
	/*
	 * judging 
	 */
    if (daysPast % 5 <= 2)
        printf ("Fishing ...\n");
    else
        printf ("Netting ...\n");
}

/*
 *@brief: check whether the year month day will make
 *		up a valid date time
 */
bool checkInput (int year, int month, int day)
{
    bool yearErr 	= false,
         monthErr 	= false,
         dayErr 	= false;
    yearErr = year < STARTYEAR || year > ENDYEAR;
    monthErr = month < 1 || month > 12;
    dayErr = day < 1 || day > tbl[isLeapYear(year)][month];

    if (yearErr)
        fprintf(stderr, "Error :invalid year specified!\n");
    if (monthErr)
        fprintf(stderr, "Error :invalid month specified!\n");
    if (dayErr)
        fprintf(stderr, "Error :invalid day specified!\n");
    if (yearErr || monthErr || dayErr)
        return false;
    else
        return true;
}

/*
 *@brief: check whether the command paramters
 *			containes three digits
 */
bool checkParameter (const char* str1,
                     const char* str2,
                     const char* str3)
{
    int year, month, day;
    if ( isdigit(*str1) &&
            isdigit(*str2) &&
            isdigit(*str3))
        return true;
    else
    {
        fprintf (stderr, "Error :invalid paramter!\n"
				"input year month day again!\n");
        return false;
    }
}

/*
 *@brief:get year month day,then check its' Legitimacy
 *		if not valid, get again.If meet end-of-file,return false
 */

bool getInput (int* year, int* month, int* day)
{
    do
    {
        if (scanf("%d%d%d", year, month, day) == EOF)
            return false;
    }while (!checkInput(*year, *month, *day));
    return true;
}


int main (int argc, char* argv[])
{
    int year, month, day;

    /*
     * input manually
     */
    if (argc != 4)
    {
        printf("This simple application will calculate the day after 1990:01:01\n"
               "end up to 2100:01:01,\n"
               "what the fishman will being doing\n");
        while (true)
        {
            printf("please input (year month day)[EOF to terminate]:\n");
            if (!getInput(&year, &month, &day))
                return EXIT_SUCCESS;
            navieQuery(year, month, day);
        }
    }
    /*
     * input from progarm paramter
     */
    else
    {
        if (!checkParameter(argv[1], argv[2], argv[3]))
            getInput(&year, &month, &day);
        else
        {
            year = strtol(argv[1], NULL, 10);
            month = strtol(argv[2], NULL, 10);
            day = strtol(argv[3], NULL, 10);
            if (!checkInput(year, month, day))
                if (!getInput(&year, &month, &day))
                    return EXIT_SUCCESS;
        }
        navieQuery(year, month, day);
    }

    return 0;
}