²ndlargestwithoutsorting.c

/*This code found the 2nd largest element without sorting the array*/
/*This code works only when all elements are distinct*/
#include<stdio.h>
#include<malloc.h>

int main()
{
   int *arr,i,j,max,n,max2;
     printf("Enter number of elements(all elements should be distinct):. ");
    scanf("%d",&n);
    arr= calloc(n,sizeof(int));
    /*Enter all (distinct) elements of array*/
    for(i=0;i<n;i++)
    {    printf("Enter element %d: ",i+1);
        scanf("%d",&arr[i]);
    }
    max=arr[0];//let first element is maximum
/*First of all found the Largest*/
    for(i=0;i<n;i++)
    {    for(j=i+1;j<n;j++)
            {    if(arr[j]>arr[i] && arr[j]>max)
                max=arr[j];
            }
    }
   //printf("\n%d",max);
/*Now to find 2nd Largest*/
max2=arr[0];
    for(i=0;i<n;i++)
    {    for(j=i+1;j<n;j++)
            {  if(arr[j]==max)
                    continue;
             if(arr[j]>arr[i])
                max2= arr[j];
            }
    }
    printf("\nSecond Largest Number = %d",max2);
    /*Printing array to show that array is not sorted*/

    printf("\n Here is the list:\n");
    for(i=0;i<n;i++)
    {    printf("%d ",arr[i]);

    }
    free(arr);

    return 0;
}