Racing Horses.py

# Racing Horses
for _ in range(int(input())):
    n = int(input())
    l = list(map(int, input().split()))
    l.sort()
    m = l[1] - l[0]
    for j in range(1, n):
        if l[j] - l[j - 1] < m:
            m = l[j] - l[j - 1]
    print(m)