Find second largest element in an array

Posted on Apr 23, 2020

C program to find second largest element in a one dimensional array.

Program

#include<stdio.h>
#include<conio.h>
#include<limits.h>
#define MAX 50

void main()
{
	int arr[MAX];
    int i, n, max, second, flag;

    printf("Enter the number of elements in the array\t:");
    scanf("%d",&n);
    printf("Enter the elements\n");
    for(i=0;i<n;i++)
    {
        printf("Element %d\t:",i+1);
        scanf("%d",&arr[i]);
    }

    max = arr[0];
    second = INT_MIN;
    flag = 0;
    for(i=0;i<n;i++)
    {
        if(arr[i] > max)
        {
            second = max;
            max = arr[i];
            flag = 1;
        }

        else if(arr[i] > second && arr[i] != max)
        {
            second = arr[i];
            flag = 1;
        }
    }

    if(flag == 0)
        printf("\nSecond Largest element does not exist");
    else
        printf("\nSecond Largest element of the array is\t:%d",second);

    getch();
}

Output

********** Run1 ********** 

Enter the number of elements in the array       :8
Enter the elements
Element 1       :4
Element 2       :5
Element 3       :1
Element 4       :2
Element 5       :6
Element 6       :9
Element 7       :8
Element 8       :7

Second Largest element of the array is  :8


********** Run2 ********** 

Enter the number of elements in the array       :4
Enter the elements
Element 1       :5
Element 2       :5
Element 3       :5
Element 4       :5

Second Largest element does not exist