C Program for Second Maximum and Second Minimun in an One-Dimensional Array

There are two approaches to calculate maximum,minimum,second-maximum and second-minimum.
The first one is through sorting.You can sort the array in ascending or descending order and can get the required degree of number i.e max,min,etc.
The second approach is without sorting.
The below code will generate 2nd max and 2nd min from a list of numbers in an array without sorting.

Logic: Find the required number using linear search

Code:

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

void main()
{
  int i,size,min,max,second_max,second_min;
  
  //get size of the array

 printf("Enter total number of elements:");
 scanf("%d",&size);

//declare an array

int numbers[size];
 
//fill the array 

 printf("Enter numbers:\n");
 for(i=0;i<size;i++)
 {
       scanf("%d",&numbers[i]);
 }

 //initialize max,min,second_max,second_min with first element of the array

 max=min=second_min=second_max=numbers[0];

 /*find the max and min numbers from the array.
    start searching from index 1 because max,min already contain the numbers at
    index 0 
  */
 


 for(i=1;i<size;i++)
 {
     /*if the number at index i is greater then the number in max 
        then put the number at i in max
     */
     
      if(max<numbers[i])
             max=numbers[i];
   
     /*if the number at index i is less then the number in min 
        then put the number at i in min
     */
 
     if(min>numbers[i])
            min=numbers[i];
 }  

 /*find the second max and second min numbers from the array
    go through the array,if the number at index i is equal to the number in max
    or min,then skip the checking process and proceed to the next number in the
    array
  */

 for(i=1;i<size;i++)
 {
     if(numbers[i]==max || numbers[i]==min)
          continue;
     
    if(second_max<numbers[i])
         second_max=numbers[i];

    if(second_min>numbers[i])
         second_min=numbers[i];
}

 //print the second max and second min numbers

 printf("\nThe second maximum number is %d\nThe second minimum number is  %d",second_max,second_min);

  printf("\npress any key to continue");
  getch();

}    

Filed Under: Arrays, loops, Simple C Programs Tuesday, 29 April 2014