题解 | 子数组绝对值的最大值

fmin = lambda x, y: x if x < y else y
fmax = lambda x, y: x if x > y else y

def solve(testcase):
    n = II()
    A = LII()
    res = 0
    m, M = 0, 0
    cur = 0

    for a in A:
        cur += a
        res = fmax(res, abs(cur - m))
        res = fmax(res, abs(M - cur))
        m = fmin(m, cur)
        M = fmax(M, cur)
    
    print(res)

for testcase in range(1):
    solve(testcase)