# Check whether array is subset of another array or not in Python

## Check whether array is subset of another array or not

In this program we will  Check whether array is subset of another array or not in Python. A subset is defined as a set whose elements are all members of another set. We will input two arrays and check whether the second array is subset of first array and display accordingly.

• Example 1:
• Array 1 -11,13,5,1,7
• Array 2 -7,5,1
• All the elements of Array 2 are present in Array 1
• Array 2 is subset of Array 1
• Example 2:
• Array 1 -23,39,51,5,4
• Array 2 -7,5,9
• All the elements of Array 2  are not present in Array 1
• Array 2 is not subset of Array 1

## Algorithm:

1. Input two arrays ar1 and ar2
2.  Initialize count c=0
3.  Iterate a for loop over the elements of ar2 and check whether elements of array 2 are present in array 1
4. Increment count if the condition is true
5. If count is equal to the length of array 2 then display “Array 2 is subset of Array 1”
6.  otherwise display “Array 2 is not subset of Array 1”

## Python Code(using array iteration):

ar1=list(map(int,input(“Enter array 1”).split()))
ar2=list(map(int,input(“Enter array 2”).split()))
c=0
x=len(ar2)
for i in ar2:
if i in ar1:
c+=1
if(c==x):
print(“Array 2 is subset of Array 1”)
else:
print(“Array 2 is not subset of Array 1”)

## Union function:

Let’s see how to check whether array is subset of another array or not using union function in Python.

In general Mathematics we know that a set is said to subset of another set if A U B = A
In set theory, the union of two sets is the set of all elements in the two sets.

• A={11 13 5 1 7}
• B={7 5 1}
• A U B ={11 13 5 1 7}
Here A U B equals to set A hence B is subset of A

## Algorithm:

• 3. Use union function to find one array is subset of another array or not

## Python code (using union function)

ar1=set(map(int,input(“Enter array 1 “).split()))
ar2=set(map(int,input(“Enter array 2 “).split()))
if(ar1.union(ar2)==ar1):
print(“Array 2 is subset of Array 1”)
else:
print(“Array 2 is not subset of Array 1”)

### Output:

`Enter array 1 11 13 5 1 7Enter array 2 7 5 1Array 2 is subset of Array 1`