1949B - Charming Meals - CodeForces Solution

for t in range(int(input())):
    n = int(input())
    a = sorted(map(int, input().split()))
    b = sorted(map(int, input().split()))
    print(max(
          min(abs(x - y) for x, y in zip(a, b[i:] + b[:i])) for i in range(n)
    ))