AA. [USACO23OPEN] Pareidolia S

    远端评测题 4000ms 256MiB

[USACO23OPEN] Pareidolia S

该比赛已结束,您无法在比赛模式下递交该题目。您可以点击“在题库中打开”以普通模式查看和递交本题。

题目背景

Note: The time limit for this problem is 4s, 2x the default.

Pareidolia is the phenomenon where your eyes tend to see familiar patterns in images where none really exist -- for example seeing a face in a cloud. As you might imagine, with Farmer John's constant proximity to cows, he often sees cow-related patterns in everyday objects. For example, if he looks at the string "bqessiyexbesszieb", Farmer John's eyes ignore some of the letters and all he sees is "bessiebessie".

题目描述

Given a string ss, let B(s)B(s) represent the maximum number of repeated copies of "bessie" one can form by deleting zero or more of the characters from ss. In the example above, B(“bqessiyexbesszieb")=2B(\text{``bqessiyexbesszieb"}) = 2.

Computing B(s)B(s) is an interesting challenge, but Farmer John is interested in solving a challenge that is even more interesting: Given a string tt of length at most 31053\cdot 10^5 consisting only of characters a-z, compute the sum of B(s)B(s) over all contiguous substrings ss of tt.

输入格式

The input consists of a nonempty string of length at most 31053\cdot 10^5 whose characters are all lowercase English letters.

输出格式

Output a single number, the total number of bessies that can be made across all substrings of the input string.

bessiebessie

14

abcdefghssijebessie

28

提示

For the first sample, twelve substrings contain exactly 11 "bessie", and 11 string contains exactly 22 "bessie"s, so the total is 121+12=1412\cdot 1+1\cdot 2=14.

  • Inputs 3-5: The string has length at most 50005000.
  • Inputs 6-12: No additional constraints.

【蒙青创】2025年CSP-J/S 冲刺【DP T4冲刺AK】

未认领
状态
已结束
题目
28
开始时间
2025-9-26 0:00
截止时间
2025-11-30 23:59
可延期
24 小时