'''
题目
给定一个数组a，返回位置i,使得sum(a[: i + 1])和sum(a[i + 1 : ])最接近
如果有多个满足条件的位置，返回最小的那个
例子
nearest_split_sum([7,3,2,8,0,-1,9]) -> 2
nearest_split_sum([1,1,0,1,1]) -> 1
nearest_split_sum([1]) -> 0
假设
输入的数组不为空
tips
利用之前的分段和计算新的分段和
代码:
'''
def nearest_split_sum(a):
res = []
mins = []
for i in range(len(a)):
if i == 0:
res.append((a[0], sum(a) - a[0]))
else:
res.append((res[-1][0] + a[i], res[-1][1] - a[i]))
mins.append(abs(res[-1][0] - res[-1][1]))
print(res)
print(mins)
print(min(mins))
return mins.index(min(mins))
# print(nearest_split_sum([7,3,2,8,0,-1,9]))# -> 2
print(nearest_split_sum([1,1,0,1,1]))# -> 1
# print(nearest_split_sum([1]))# -> 0
# print(nearest_split_sum([1,2,3]))# -> 1
