Find the largest number in a series by using pointers in C language

Pointer is a variable that stores the address of another variable. We can hold the null values by using pointer. It can be accessed by using pass by reference. Also, there is no need of initialization, while declaring the variable.

The syntax for pointer is as follows −

pointer variable= & another variable;

For example,

p =&a;

Algorithm

Refer an algorithm given below for finding the largest number in a series with the help of pointers.

Step 1: Start
Step 2: Declare integer variables
Step 3: Declare pointer variables
Step 4: Read 3 numbers from console
Step 5: Assign each number address to pointer variable
Step 6: if *p1 > *p2
if *p1 > *p3
print p1 is large
else
print p2 is large
Step 7: Else if *p2 > *p3
Print p2 is large
Else
Print p3 is large
Step 8: Stop

Program

Following is the C program to find the largest number in a series by using pointers −

 Live Demo

#include <stdio.h>
int main(){
   int num1, num2, num3;
   int *p1, *p2, *p3;
   printf("enter 1st no: ");
   scanf("%d",&num1);
   printf("enter 2nd no: ");
   scanf("%d",&num2);
   printf("enter 3rd no: ");
   scanf("%d",&num3);
   p1 = &num1;
   p2 = &num2;
   p3 = &num3;
   if(*p1 > *p2){
      if(*p1 > *p3){
         printf("%d is largest ", *p1);
      }else{
         printf("%d is largest ", *p3);
      }
   }else{
      if(*p2 > *p3){
         printf("%d is largest ", *p2);
      }else{
         printf("%d is largest ", *p3);
      }
   }
   return 0;
}

Output

When the above program is executed, it produces the following result −

Run 1:
enter 1st no: 35
enter 2nd no: 75
enter 3rd no: 12
75 is largest
Run 2:
enter 1st no: 53
enter 2nd no: 69
enter 3rd no: 11
69 is largest