C Program to find union and intersection of two arrays

In this program, You will learn how to find union and intersection of two arrays in c.

---

#include<stdio.h>

int main(){
   //statement
}

Example: How to find union and intersection of two arrays in c.

#include<stdio.h>

void printUnion(int arr1[], int arr2[], int len1, int len2) {

    int f, i, j, k = 0;
    int arr3[100];

    for (i = 0; i < len1; i++) {
        arr3[k] = arr1[i];
        k++;
    }

    for (i = 0; i < len2; i++) {
        f = 0;
        for (j = 0; j < len1; j++) {
            if (arr2[i] == arr1[j]) {
                f = 1;
            }
        }

        if (f == 0) {
            arr3[k] = arr2[i];
            k++;
        }
    }
    printf("Union of two array is:");
    for (i = 0; i < k; i++) {
        printf("%d ", arr3[i]);
    }
}

void printIntersection(int arr1[], int arr2[], int len1, int len2) {

    int arr3[100];
    int i, j, k = 0;

    for (i = 0; i < len1; i++) {
        for (j = 0; j < len2; j++) {
            if (arr1[i] == arr2[j]) {
                arr3[k] = arr1[i];
                k++;
            }
        }
    }
    printf("\nIntersection of two array is:");
    for (i = 0; i < k; i++) {
        printf("%d ", arr3[i]);
    }
}

int main() {

    int arr1[100];
    int arr2[100];
    int arr3[100];
    int i, j, len1, len2;

    printf("Enter size of 1st array:");
    scanf("%d", &len1);

    printf("Enter 1st array elements:");
    for (i = 0; i < len1; i++) {
        scanf("%d", &arr1[i]);
    }

    printf("Enter size of 2nd array:");
    scanf("%d", &len2);

    printf("Enter 2nd array elements:");
    for (i = 0; i < len2; i++) {
        scanf("%d", &arr2[i]);
    }

    printUnion(arr1, arr2, len1, len2);
    printIntersection(arr1, arr2, len1, len2);

    return 0;
}

Output:

Enter size of 1st array:4                                                                                                              
Enter 1st array elements:2 3 4 5                                                                                                       
Enter size of 2nd array:4                                                                                                              
Enter 2nd array elements:3 4 5 6                                                                                                       
Union of two array is:2 3 4 5 6                                                                                                        
Intersection of two array is:3 4 5