Submission #719773

#	Time	Username	Problem	Language	Result	Execution time	Memory
719773		Boomyday	Fancy Fence (CEOI20_fancyfence)	Pypy 3	30 / 100	132 ms	37084 KiB

fancyfence

MOD = 1000000007
inv2 = pow(2, MOD-2, MOD)

def calc_num(w, h):
    return w*(w+1)*h*(h+1)*inv2*inv2 % MOD



N = int(input())

h, w = [0], [0]

h += list(map(int, input().split()))
w += list(map(int, input().split()))

rsm = 0
scr = 0

for i in range(N, 0, -1):
    rsm += w[i]
    scr += calc_num(rsm, h[i]) - calc_num(rsm, h[i-1])
    scr %= MOD
print(scr)

• Subtask 1: 0 / 0
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 0 / 18
• Subtask 7: 0 / 27