All C programmes written here are working and tested with outputs mentioned. Check out them all!

  (CPU: Computer Programming and Utilization, 1st SEM )

List of C Programmes in this post,

1. Hello world in C language

//C hello world example
#include <stdio.h>
 
int main()
{
  printf("Hello world\n");
  return 0;
}

2. C program to perform addition, subtraction, multiplication, modulo and division. Numbers are assumed to be integers and will be entered by the user.

#include <stdio.h>
 
int main()
{
   int first, second, add, subtract, multiply, modulo;
   float divide;
 
   printf("Enter two integers\n");
   scanf("%d%d", &first, &second);
 
   add = first + second;
   subtract = first - second;
   multiply = first * second;
   modulo = first % second;
   divide = first / (float)second;   //typecasting
 
   printf("Sum = %d\n",add);
   printf("Difference = %d\n",subtract);
   printf("Multiplication = %d\n",multiply);
   printf("Modulo = %d\n",modulo);
   printf("Division = %.2f\n",divide);
 
   return 0;
}

3. Write a c program to find the area of a triangle.

#include<stdio.h>
#include<math.h>
int main()
{
 float a,b,c;
 float s,area;
 printf("Enter size of each sides of triangle");
 scanf("%f%f%f",&a,&b,&c);

 s = (a+b+c)/2;
 area = sqrt(s*(s-a)*(s-b)*(s-c));
 printf("Area of triangle is: %.3f",area);

 return 0;

}

4. C program for area of circle

#include<stdio.h>int main() 

{float radius, area;
printf("\nEnter the radius of Circle : ");
scanf("%d", &radius);
area = 3.14 * radius * radius;
printf("\nArea of Circle : %f", area);
return (0);
}

/* Program to convert Centigrade to Fahrenheit and vice versa */

int main()
{
int fahr,cel,choice;

printf("What do you want to do?(1/2)\n1. fahrenheit to Celsius\n2. Celsius to Fahrenheit\n");
scanf("%d",&choice);

switch(choice)
{
case 1:
printf("Enter fahrenheit value\n");
scanf("%d",&fahr);
cel=(fahr-32)*5/9;
printf("Celsius of %d degrees fahrenheit is %d degrees celsius\n\n",fahr,cel);

case 2:
printf("Enter celsius value\n");
scanf("%d",&cel);
fahr=(1.8*cel) + 32;
printf("Fahrenheit of %d degrees Celsius is %d degrees fahrenheit\n\n",cel,fahr);
}
}

6. A program which accepts a character from the keyboard and displays it with use of getchar() and putchar()

#include<stdio.h>
#include<conio.h>
void main()
{
    char x;
    clrscr();
    x= getchar();
    putchar(x);
    getch();
}

7. C program to swap two numbers

#include <stdio.h>
 
int main()
{
   int x, y, temp;
 
   printf("Enter the value of x and y\n");
   scanf("%d%d", &x, &y);
 
   printf("Before Swapping\nx = %d\ny = %d\n",x,y);
 
   temp = x;
   x    = y;
   y    = temp;
 
   printf("After Swapping\nx = %d\ny = %d\n",x,y);
 
   return 0;
}

8. C Program to Find the Largest Number Among Three Numbers

/* C program to find largest number using if statement only */

#include <stdio.h>
int main(){
      float a, b, c;
      printf("Enter three numbers: ");
      scanf("%f %f %f", &a, &b, &c);
      if(a>=b && a>=c)
         printf("Largest number = %.2f", a);
      if(b>=a && b>=c)
         printf("Largest number = %.2f", b);
      if(c>=a && c>=b)
         printf("Largest number = %.2f", c);
      return 0;
}

9. Program to perform arithmetic operations using switch statement

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>

void main()
{
int ch;
float a,b,res;
clrscr();
printf(“Enter two numbers:”);
scanf(“%f%f”,&a,&b);
printf(“\nMenu \n1.Addition \n2.Subtraction \n3.Multiplication \n4.Division \n5.Modulo”);
printf(“\nEnter your choice:”);
scanf(“%d”,&ch);

switch(ch)
{
case 1: res=a+b;
break;
case 2: res=a-b;
break;
case 3: res=a*b;
break;
case 4: res=a/b;
break;
case 5: res=a%b
break;
default: printf(“Dude,Wrong choice!!\nPress any key…”);
getch();
exit(0);
}

printf(“\nResult=%f”,res);
getch();
} 

10. C program to check whether a character is Capital, Small case letter, digit or special symbol

#include <stdio.h>
#include<conio.h>
void main()
{
    char ch;
    clrscr();
    printf("Enter one character\n");
    scanf("%c", &ch);
    if ((ch>='0')&&(ch<='9'))
    printf("The character %c is digit\n",ch);
else if ((ch>='a')&&(ch<='z'))
    printf("The character %c is Lower case\n",ch);
else if ((ch>='A')&&(ch<='Z'))
    printf("The character %c is Upper case\n",ch);
else 
     printf("The character %c is other symbol\n",ch);
getch();
}

11. C Program to Find the Sum of First N Natural Numbers

/* C program to find the sum of 'N' natural numbers*/

    #include <stdio.h>

    void main()
  {
     int i, num, sum = 0;

     printf("Enter an integer number \n");
     scanf ("%d", &num);

     for (i = 1; i <= num; i++)

        {

           sum = sum + i;

        }

        printf ("Sum of first %d natural numbers = %d\n", num, sum);

    }

#include <stdio.h>
#include<conio.h>
void main()
{
     int x,y,max,min;
     clrscr();
     printf("Give two integer numbers\n");
     scanf("%d %d", &x,&y);
     
     max=(x>y)? x:y ;
     min=(x<y)? x:y;
     
     printf("Maximum of %d and %d is = %d\n",x,y,max);
     printf("Minimum of %d and %d is = %d\n",x,y,min);
getch();
}

#include <stdio.h>
#include<conio.h>
void main()
{
     int x;
     int mul,div;
     clrscr();
     
     printf("Give one integer number\n");
     scanf("%d",&x);
     
     mul = x << 1;  /*left shift*/
     div = x >>1; /*right shift*/
     
     printf("Multiplication of %d by 2 = %d\n",x,mul);
     printf("Division of %d by 2 = %d\n",x,div);
getch();
}