题解 | #小红的抛弃后缀#
小红的抛弃后缀
https://ac.nowcoder.com/acm/problem/271172
前缀和,把时间复杂度降到O(n)
l = [int(i) for i in input().strip()][::-1]
lenl = len(l)
sum1 = sum(l)
if sum1%9 == 0:
cnt = 1
else:
cnt = 0
for i in range(lenl-1):
sum1 -= l[i]
if sum1%9 == 0:
cnt += 1
print(cnt)