inp = lambda : list(map(int,input().split()))
for _ in range(int(input())):
n = int(input())
a = inp()
ans = 0
d = 0
for i in range(1,n):
if a[i-1] > a[i]:
if a[i-1] > a[i] + d:
ans += 2*(a[i-1] - a[i] - d) + d
d = a[i-1] - a[i]
else:
ans += a[i-1] - a[i]
a[i] = a[i-1]
print(ans)1032. Stream of Characters | 987. Vertical Order Traversal of a Binary Tree |
952. Largest Component Size by Common Factor | 212. Word Search II |
174. Dungeon Game | 127. Word Ladder |
123. Best Time to Buy and Sell Stock III | 85. Maximal Rectangle |
84. Largest Rectangle in Histogram | 60. Permutation Sequence |
42. Trapping Rain Water | 32. Longest Valid Parentheses |
Cutting a material | Bubble Sort |
Number of triangles | AND path in a binary tree |
Factorial equations | Removal of vertices |
Happy segments | Cyclic shifts |
Zoos | Build a graph |
Almost correct bracket sequence | Count of integers |
Differences of the permutations | Doctor's Secret |
Back to School | I am Easy |
Teddy and Tweety | Partitioning binary strings |