C Program to Find Unique Elements in an Array

In this post, we will learn how to find the unique elements in an array, such that the repetitive elements in the array will be displayed only once.

Let's write a C program to find unique elements in an array.

C Program to Find Unique Elements in an Array

Let's create a file named uniqueelements.c and add the following source code to it.

#include<stdio.h> 
#define max 100

int ifexists(int z[], int u, int v)
{
	int i;
	for (i=0; i<u;i++)
		if (z[i]==v) return (1);
	return (0);
}


void main()
{
	int p[max], q[max];
	int m;
	int i,k;
	k=0;
	printf("Enter length of the array:"); 
	scanf("%d",&m); 
	printf("Enter %d elements of th array\n",m); 
	for(i=0;i<m;i++ )
		scanf("%d",&p[i]); 
	q[0]=p[0];
	k=1;
	for (i=1;i<m;i++)
	{
		if(!ifexists(q,k,p[i]))
		{
			q[k]=p[i];
			k++;
		}
	}
	printf("\nThe unique elements in the array are:\n"); 

	for(i = 0;i<k;i++)
		printf("%d\n",q[i]); 
}

To compile and run the above C program, you can use C Programs Compiler Online tool.

Output:

Enter the length of the array:5
Enter 5 elements in the array
1
2
3
2
1

The unique elements in the array are:
1
2
3




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