C Program to find union of two sets

#include<stdio.h>
#include<conio.h>
void main()
{
 int A[10],B[10],C[10],i,j,k=0,n,m,flag=0;
 clrscr();
 printf("Enter the size of array A");
 scanf("%d",&n);
 printf("Enter the element of First array A");
   for(i=0;i<n;i++)
     {
       scanf("%d",&A[i]);
     }
     printf("Enter the size of array B");
 scanf("%d",&m);
 printf("Enter the elements of array B");
   for(j=0;j<m;j++)
     {
       scanf("%d",&B[j]);
     }
for(i=0;i<n;i++)
 {
  C[k]=A[i];
  k++; }
for(i=0;i<n;i++)
 {
 flag=0;
  for(j=0;j<m;j++)
   {
    if(B[i]==C[j])
     {
     flag==1;
     break;
     }
   }
if(flag==0)
 {
  C[k]=B[i];
  k++;
 }}
printf("\n union\n");
for(i=0;i<k;i++)
{
printf("%d",C[i]);
}
getch();}
 
OUTPUT:-

C Program to find GCD (Greatest Common Divisor) of two numbers

#include<stdio.h>
#include<conio.h>
void main()
{
int m,i,x,y;
clrscr();
printf("Enter the two number");
scanf("%d%d",&x,&y);
if(x>y)
m=y;
else
m=x;
for(i=m;i>=1;i--)
{
if(x%i==0&&y%i==0)
{
printf("\n HCF is %d",i);
break;
}
}
getch();
}

OUTPUT-