集合A-B python

集合A-B python

 

n = int(input())
for i in range(n):
    a = []
    b = []
    m = input()
    q = list(m.split())
    for i in range(2,2+int(q[0])):
        a.append(q[i])
    for i in range(2+int(q[0]),len(q)):
        b.append(q[i])
    c=set(a)-set(b)
    c=list(c)
    c.sort()
    if len(c)==0:
        print("NULL")
    else:
        print(*c)