Basic Example Of C

C Program to check whether the given integer is positive or negative 

/* Description: A program to check whether the input
 * integer number is positive or negative. 
 * Written by: Santosh Asole
 */
#include <stdio.h>
 
void main()
{
    int num;
 
    printf("Enter a number: \n");
    scanf("%d", &num);
    if (num > 0)
        printf("%d is a positive number \n", num);
    else if (num < 0)
        printf("%d is a negative number \n", num);
    else
        printf("0 is neither positive nor negative");
}

Output 1:

Enter a number:
0
0 is neither positive nor negative

Output 2:

Enter a number:
-3
-3 is a negative number

Output 3:

Enter a number:
100
100 is a positive number

Program to find largest of three input numbers

#include<stdio.h>
int main()
{
   int num1,num2,num3;
   
   //Ask user to input any three integer numbers
   printf("\nEnter value of num1, num2 and num3:");
   //Store input values in variables for comparsion
   scanf("%d %d %d",&num1,&num2,&num3);

   if((num1>num2)&&(num1>num3))
      printf("\n Number1 is greatest");
   else if((num2>num3)&&(num2>num1))
      printf("\n Number2 is greatest");
   else
      printf("\n Number3 is greatest");
   return 0;
}
Output:
Enter value of num1, num2 and num3: 15 200 101
 Number2 is greatest