Codeforces Round 917 (Div. 2)
B
Erase First or Second Letter
Codeforces
1100
原题
← AC →
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You are given a string $s$ of length $n$. Let's define two operations you can apply on the string:

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  • remove the first character of the string;
  • remove the second character of the string.
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Your task is to find the number of distinct non-empty strings that can be generated by applying the given operations on the initial string any number of times (possibly zero), in any order.

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Input

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Each test consists of multiple test cases. The first line contains a single integer $t$ ($1 \leq t \leq 10^4$) — the number of test cases. The description of the test cases follows.

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The first line of each test case contains $n$ ($1 \leq n \leq 10^5$) — the length of the string.

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The second line of each test case contains the string $s$. It is guaranteed that the string only contains lowercase letters of the English alphabet.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

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Output

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For each test case, output a single integer: the number of distinct non-empty strings you can get.

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Note

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In the first test case, we can get the following strings: $a$, $aa$, $aaa$, $aaaa$, $aaaaa$.

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In the third test case, for example, the word $ba$ can be reached in the following way:

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  • remove the first character of the current string $ababa$, getting $baba$;
  • remove the second character of the current string $baba$, getting $bba$;
  • remove the second character of the current string $bba$, getting $ba$.
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样例

Input #1
5
5
aaaaa
1
z
5
ababa
14
bcdaaaabcdaaaa
20
abcdefghijklmnopqrst
Output #1
5
1
9
50
210
InputCopy OutputCopy
题目信息
题号
1917B
时间限制
1 s
内存限制
256 MB
标签
暴力
组合数学
数据结构
动态规划
字符串

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