# C Program Count Number of Duplicate Elements in An Array

In this tutorial, i am going to show you how to count the number of duplicate elements in an array with the help of standard method and function in c programs.

## All C Programs Count Number of Duplicate Elements in An Array

• C Program Count Number of Duplicate Elements in An Array using Standard Method
• C Program Count Number of Duplicate Elements in An Array using Function

### C Program Count Number of Duplicate Elements in An Array using Standard Method

```#include <stdio.h>
int main()
{
int a[10000],b[10000],i,j,n,c=0 ;

printf("Enter size of the array : ");
scanf("%d", &n);

printf("Enter elements in array : ");
for(i=0; i<n; i++)
{
scanf("%d",&a[i]);
}

for(i=0; i<n; i++)
{
if(a[i]!=-1)
{
for(j=i+1; j<n; j++)

{
if(a[i]==a[j])
{
c++;
a[j]=-1;
}
}
}

}

printf("duplicate numbers in the  array: %d",c);

return 0;
}```

The result of the above c program; as follows:

```Enter size of the array : 5
Enter elements in array : 1 2 5 4 4
duplicate numbers in the  array: 1```

### C Program Count Number of Duplicate Elements in An Array using Function

```#include <stdio.h>

count(int *a,int n)
{
int i,c=0,j;
for(i=0; i<n; i++)
{
if(a[i]!=-1)
{
for(j=i+1; j<n; j++)

{
if(a[i]==a[j])
{
c++;
a[j]=-1;
}
}
}

}
return c;

}

int main()
{
int a[10000],b[10000],i,n,c;

printf("Enter size of the array : ");
scanf("%d", &n);

printf("Enter elements in array : ");
for(i=0; i<n; i++)
{
scanf("%d",&a[i]);
}

c=count(a,n);

printf("duplicate numbers in the  array: %d",c);

return 0;
}```

The result of the above c program; as follows:

```Enter size of the array : 5
Enter elements in array : 11 11 22 22 33
duplicate numbers in the  array: 2```

Categories C