To Be Familiarize With Control Structures ( If Else )

1. WAP to find the largest among 3 numbers you entered ( use nested if else )
2. WAP to check in whether the year is leap year or not. 
3. WAP to find all the roots of a quadratic equation using switch statement.
4. WAP to display the 12 months names according to numbers you entered.
5. WAP to enter one of +, - , *, / operator and other two integer operands  and display the result.

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1. Question 1

#include <stdio.h>
#include <conio.h>
void main ()
{
int a,b,c;
clrscr ();
printf ("Enter three numbers\n");
scanf ("%d%d%d",&a,&b,&c);
if (a>b)
{
if (a>c)
printf ("%d is largest number\n",a);
else
printf ("%d is the largest number\n",c);
}
else
{
if (b>c)
printf ("%d is the largest number\n",b);
else
printf ("%d is the largest number",c);
}
getch ();
}

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2. Question 2

#include <stdio.h>
#include <conio.h>
void main ()
{
int a;
clrscr ();
printf ("Enter a year\n");
scanf ("%d",&a);
if (a%4==0)
{
if (a%100==0)
{
if (a%400==0)
printf ("%d is leap year\n",a);
else
printf ("%d is not leap year\n",a);

}
else
printf ("%d is leap year\n",a);
}
else
printf ("%d is not leap year\n",a);
getch ();
}

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3. Question 3

#include <stdio.h>
#include <conio.h>
#include <math.h>
void main ()
{
float a,b,c;
float disc,real,imag;
float R1,R2;
clrscr ();
printf ("Enter a b c for quadratic equation:\n");
scanf ("%f%f%f",&a,&b,&c);
disc=b*b-4.0*a*c;
real=-b/(2.0*a);
imag=sqrt(abs(disc))/(2.0*a);
switch (disc>0)
       { case 1:
R1=real+imag;
R2=real-imag;
printf ("Roots are real and distinct:\nRoot1=%f\nRoot2=%f\n",R1,R2);
break;

case 0:
switch (disc<0)
       { case 1:
printf ("Roots are imaginary:\nRoot1=%f+i%f\n",real,imag);
printf ("Root2=%f-i%f\n",real,imag);
break;
case 0:
R1=real;
R2=R1;
printf ("Roots are real and equal:\nRoot1=%f\nRoot2=%f\n",R1,R2);
break;

}

       }
       getch ();
}

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4. Question 4

#include <stdio.h>
#include <conio.h>
void main ()
{
int a;
clrscr ();
printf ("Enter a number from 1 to 12:\n");
scanf ("%d",&a);
if (a==1)
printf ("January\n");
else if (a==2)
printf ("February\n");
else if (a==3)
printf ("March\n");
else if (a==4)
printf ("April\n");
else if (a==5)
printf ("May\n");
else if (a==6)
printf ("June\n");
else if (a==7)
printf ("July\n");
else if (a==8)
printf ("August\n");
else if (a==9)
printf ("September\n");
else if (a==10)
printf ("October\n");
else if (a==11)
printf ("November\n");
else if (a==12)
printf ("December\n");
else
printf ("Dont you understand English\n");
getch ();
}

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5. Question 5

#include <stdio.h>
#include <conio.h>
#include <math.h>
void main ()
{
char op;
int a,b,r;
clrscr ();
printf ("Enter first number: ");
scanf ("%d",&a);
printf ("Enter operator: ");
scanf (" %c",&op);
printf ("Enter second number: ");
scanf ("%d",&b);
switch (op)
{
case '+':
r=a+b;
//printf ("Result is %d",r);
break;
case '-':
r=a-b;
//printf ("Result is %d",r);
break;
case '*':
r=a*b;
//printf ("Result is %d",r);
break;
case '/':
r=a/b;
//printf ("Result is %d",r);
break;
default: printf ("Invalid operator.");
}

getch ();
}