Delete duplicate elements from an array

Posted on Apr 24, 2020

C program to delete duplicate elements from an array.

Program

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

void read_array(int a[MAX], int n)
{
    int i;
    for(i=0;i<n;i++)
    {
        printf("Element %d\t:",i+1);
        scanf("%d",&a[i]);
    }
}

void print_array(int a[MAX], int n)
{
    int i;
    for(i=0;i<n;i++)
    {
        printf("Element %d\t:%d\n",i+1,a[i]);
    }
}

void delete(int a[MAX], int n)
{
    int i, j, k;

    for(i=0;i<n;i++)
    {
        for(j=i+1;j<n;j++)
        {
            if(a[i]==a[j])
            {
                for(k=j;k<n;k++)
                {
                    a[k] = a[k+1];
                }
                n = n-1;
                //If shifting of elements occur then don't increment j
                j--;
            }
        }
    }
    printf("\nModified array is\n");
    print_array(a, n);
}

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

    printf("Enter the number of elements in the array\t:");
    scanf("%d",&n);

    printf("Enter the elements of the array\n");
    read_array(arr, n);

    delete(arr, n);

    getch();
}

Output

Enter the number of elements in the array       :8
Enter the elements of the array
Element 1       :12
Element 2       :23
Element 3       :45
Element 4       :12
Element 5       :45
Element 6       :23
Element 7       :65
Element 8       :23

Modified array is
Element 1       :12
Element 2       :23
Element 3       :45
Element 4       :65