pvjc19cv4/program.c

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

int main()
{
        int d = 0;
        int m = 0;
        int y = 0;
        scanf("%d.%d.%d", &d, &m, &y);
    
        //check date validness
        if((y>=0 && y<=9999) && (m>=1 && m<=12) && (((d>=1 && d<=31) && (m==1 || m==3 || m==5 || m==7 || m==8 || m==10 || m==12)) || ((d>=1 && d<=30) && m==4 || m==6 || m==9 || m==11) || ((d>=1 && d<=28) && m==2) || (d==29 && m==2 && (y%400==0 ||(y%4==0 && y%100!=0))))){
        }else{
                puts("Nespravny datum");
                return 0;
        }
        //setting date
        struct tm t = { .tm_year=y-1900, .tm_mon=m-1, .tm_mday=d };
        //adding week to the date
        t.tm_mday += 7;
        mktime(&t);

        //output data
        if(t.tm_mday <10 && t.tm_mon+1 < 10)
		printf(" %d.0%d.%d\n\n", t.tm_mday, t.tm_mon+1, t.tm_year+1900);
	else if(t.tm_mday < 10)
		printf(" %d.%d.%d\n\n", t.tm_mday, t.tm_mon+1, t.tm_year+1900);
	else if(t.tm_mon+1 < 10)
		printf("%d.0%d.%d\n\n", t.tm_mday, t.tm_mon+1, t.tm_year+1900);
        else
                printf("%d.%d.%d\n\n", t.tm_mday, t.tm_mon+1, t.tm_year+1900);

}