[zerojudge] d563: 等值首尾和

from sys import stdin
from itertools import accumulate
# accumulate([1,2,3,4,5]) --> 1 3 6 10 15
# https://docs.python.org/3/library/itertools.html#itertools.accumulate

f = [int(x) for x in stdin.readline().split()][1:]
a = set(accumulate(f))
b = set(accumulate(f[::-1]))
c = a & b
print(len(c))

'''
這題測資沒有斷行
所以 input 取  f[1:]
以  7 3 6 2 1 4 5 2
f = [3, 6, 2, 1, 4, 5, 2]
accumulate(f) =       [3, 9, 11, 12, 16, 21, 23] # 從前面累計
accumulate(f[::-1]) = [2, 7, 11, 12, 14, 20, 23] # 從後面累計
a = set(accumulate(f)) =       {3, 9, 11, 12, 16, 21, 23}
b = set(accumulate(f[::-1])) = {2, 7, 11, 12, 14, 20, 23}
c = a & b 是交集
print(len(c)) 交集的個數
'''