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)
780C - Andryusha and Colored Balloons | 1153A - Serval and Bus |
1487C - Minimum Ties | 1136A - Nastya Is Reading a Book |
1353B - Two Arrays And Swaps | 1490E - Accidental Victory |
1335A - Candies and Two Sisters | 96B - Lucky Numbers (easy) |
1151B - Dima and a Bad XOR | 1435B - A New Technique |
1633A - Div 7 | 268A - Games |
1062B - Math | 1294C - Product of Three Numbers |
749A - Bachgold Problem | 1486B - Eastern Exhibition |
1363A - Odd Selection | 131B - Opposites Attract |
490C - Hacking Cypher | 158B - Taxi |
41C - Email address | 1373D - Maximum Sum on Even Positions |
1574C - Slay the Dragon | 621A - Wet Shark and Odd and Even |
1395A - Boboniu Likes to Color Balls | 1637C - Andrew and Stones |
1334B - Middle Class | 260C - Balls and Boxes |
1554A - Cherry | 11B - Jumping Jack |