# C program to find union of two sets.

** what is union of two set:-**

** if ** A={1,1,2,3} and B={5,6,7,8} are two sets then union of the set

A and B is :-

A ∪ B ={1,2,3,5,6,7,8}

**Program:-**

Here A and B is the two sets and C is the union of set A and B.

#include<stdio.h>

#include<conio.h>

void main()

{

int a[10],b[10],i,c[10],j,k=0,n1,n2;

// taking input set A

printf(“Enter number of element of set An”);

scanf(“%d”,&n1);

printf(“Enter the element of set A n”);

for(i=0;i<n1;i++)

scanf(“%d”,&a[i]);

// taking input set B

printf(“Enter number of element of set Bn”);

scanf(“%d”,&n2);

printf(“Enter the element of set B n”);

for(i=0;i<n2;i++)

scanf(“%d”,&b[i]);

// logic for calculate union

// copy the element of set A in set C

for(i=0;i<n1;i++)

{

// repeted element is not allowed so we check is any value repeted

for(j=0;j<k;j++)

{

if(c[j]==a[i])

break;

}

if(j==k) //if not repesated then store value in set c

{

c[k]=a[i];

k++;

}

}

// copy element of set B in set C

for(i=0;i<n2;i++)

{

// check for repeted element

for(j=0;j<k;j++)

{

if(c[j]==b[i])

break;

}

if(j==k) // if element is not repeted then store in set C

{

c[k]=b[i];

k++;

}

}

// printing of union of set A and set B

printf(“Union of set A and B is:-n”);

for(i=0;i<k;i++)

printf(“%d “,c[i]);

}

**Output:-**

Enter number of element of set A

3

Enter the element of set A

1 1 2

Enter number of element of set B

4

Enter the element of set B

3 4 5 2

Union of set A and B is:-

1 2 3 4 5