题解 | 最大子数组和

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()

    if all (a <= 0 for a in A):
        print(max(A))
        return
    
    res = 0
    cur = 0

    for a in A:
        cur += a
        if cur < 0:
            cur = 0
        res = fmax(res, cur)
    
    print(res)

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