Help me in solving PREFSUMMNMAX problem

help
,
1

My issue

unable to solve this question “Prefix Suffix Min Max”

My code

# cook your dish here
t=int(input())
for i in range(t):
    n = int(input())
    b = list(map(int, input().split()))
    a = []
    maxi = 0
    sumi = 0
    for j in range(n):
        a.append(b[j]+maxi-sumi)
        sumi+=a[j]
        maxi = max(maxi,a[j])
    print(a)

Problem Link: Prefix Suffix Min Max Practice Coding Problem