Design the test cases and test the program of Previous Date problem by using Boundary Value Analysis

In this, we will test our program to check whether it can give the previous date as an output or not. We are supposing interval [2000,2050]  for year, [1,31] days for date, [1,12] for month. If we observe closely, we require to figure out whether the year input is a leap year or not between the selected year interval.

We will be applying Boundary Value Analysis to generate test cases.  The expected output can be  [Invalid date, previous Date].

Program:

#include<conio.h>
#include<stdio.h>
void main()
{
	int month,date,year, valid=-1,leap_year=-1;
	printf("please enter a date = ");
	scanf("%d",&date);
		printf("please enter a month = ");
	scanf("%d",&month);
		printf("please enter a year = ");
	scanf("%d",&year);
	if((date>0 && date<=31)&&(month>=1 && month<=12)&&(year>=2000 && year<=2050))
	{
	// finding given input is a leap year or not
	if((year%4)==0)
	{
		leap_year=1;
    if((year%100)==0)
    {
	if((year%400)==0)
	{
		leap_year=1;	
	}
	else
	{
	leap_year=-1;	
	}
}
}
if(month==2 && leap_year==1 && date >29)
valid=-1;
else if(month==2 && leap_year==-1 && date >28)
valid=-1;
else 
valid=1;
}

if((month==6 || month==4||month==9||month==11) && date>30)
valid=-1;

// validating & finding output


if(valid==1)
{
	printf("Entered date = %d-%d-%d",date,month,year);

if(date==1)
{
if(month==1)
{
date=31;
month=12;
year--;
}
else if(leap_year=1 && month==3)
{
	date=29;
	month--;
}
else if(leap_year==-1 && month==3)
{
	date=28;
	month--;
}
else if(month==2||month==4||month==6||month==8||month==9||month==11){
	date=31;
	month--;
}else{
	date=30;
	month--;
}
}
else{
	
	date--;
}
printf("\nPrevious date = %d-%d-%d \n",date,month,year);
}
else
printf("\n Not a valid date");

getch();
}

So, there will be 4N+ 1 test cases that is 4*3 +1 =13 in this case as we are using boundary value analysis.

Testing the program:

Invalid Date:

Previous Date: