1734A - Select Three Sticks - CodeForces Solution

t=int(input())
for ii in range(t):
    n=int(input())
    a=list(map(int,input().split()))
    a.sort()
    ans=999999999999
    for i in range(n-2):
        ans=min(ans,abs(a[i]-a[i+1])+abs(a[i+2]-a[i+1]))
    print(ans)