Find the Union and Intersection of the two sorted arrays in C

October 12, 2022

Union and Interaction of the two sorted arrays in C

Here, in this page we will discuss the program to find the union and interaction of two sorted arrays in C . We are given with two sorted arrays and we have to find the union and interaction of the given two arrays.

Example : Input : arr1[4] = {1, 6, 9 ,10}     arr2[3] = {10, 11, 90}

                  Output :  Union = 1 6 9 11 90

                                  Interaction = 10

Union and Interaction of the two sorted arrays in C

Algorithm to find Union :

  • Use two index variables i and j, initial values i = 0, j = 0
  • If arr1[i] is smaller than arr2[j] then print arr1[i] and increment i.
  • If arr1[i] is greater than arr2[j] then print arr2[j] and increment j. 
  • If both are same then print any of them and increment both i and j.
  • Print remaining elements of the larger array.

Algorithm to find Interaction :

  • Use two index variables i and j, initial values i = 0, j = 0.
  • If arr1[i] is smaller than arr2[j] then increment i.
  • If arr1[i] is greater than arr2[j] then increment j.
  • If both are same then print any of them and increment both i and j.
Union and intersection in C

Code to find Union and Interaction of the two sorted arrays in C

#include <stdio.h>
void printUnion(int arr1[], int arr2[], int m, int n)
{
  int i = 0, j = 0;
  while (i < m && j < n) {
    if (arr1[i] < arr2[j])
     printf("%d ",arr1[i++]);

    else if (arr2[j] < arr1[i])
     printf("%d ",arr2[j++]);

    else {
     printf("%d ",arr2[j++]);
     i++;
    }
  }

  /* Print remaining elements of the larger array */
  while (i < m)
   printf("%d ",arr1[i++]);

  while (j < n)
   printf("%d ",arr2[j++]);
}

void printIntersection(int arr1[], int arr2[], int m, int n)
{
  int i = 0, j = 0;
  while (i < m && j < n) {
     if (arr1[i] < arr2[j])
      i++;
     else if (arr2[j] < arr1[i])
      j++;
     else /* if arr1[i] == arr2[j] */
     {
       printf("%d ",arr2[j]);
       i++;
       j++;
     }
    }
}

/* Driver program to test above function */
int main()
{ 
   int m, n;

   scanf("%d", &m);

   int arr1[m];

   for(int i=0; i<m; i++) scanf("%d", &arr1[i]);

   scanf("%d", &n);

   int arr2[n];

   for(int i=0; i<n; i++) scanf("%d", &arr2[i]);

   // Function calling
  printf("Union : ");
  printUnion(arr1, arr2, m, n);


  printf("\nIntersection ");
  printIntersection(arr1, arr2, m, n);

  return 0;
}
Output :

5

1 2 3 4 5

4

1 2 3 4

Union : 1 2 3 4 5

Intersection : 1 2 3 4

Given an array which consists of only 0, 1 and 2

Find the “Kth” max and min element of an array

Find the Union and Intersection of the two sorted arrays

Find Largest sum contiguous Subarray

Minimize the maximum difference between heights 

Prime Course Trailer

Related Banners

Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription

Get Prime