Consecutive

AtCoder

IDabc328_c

Time2000ms

Memory256MB

Difficulty—

You are given a string $S = S_1S_2\ldots S_N$ of length $N$ consisting of lowercase English letters. Additionally, you are given $Q$ queries about the string $S$. For $i = 1, 2, \ldots, Q$, the $i$\-th query is represented by two integers $l_i, r_i$ and asks the following. > In the substring $S_{l_i}S_{l_i+1}\ldots S_{r_i}$ of $S$, which ranges from the $l_i$\-th to the $r_i$\-th character, how many places are there where the same lowercase English letter occurs twice in a row? In other words, how many integers $p$ satisfy $l_i \leq p \leq r_i-1$ and $S_p = S_{p+1}$? Print the answer for each of the $Q$ queries. ## Constraints * $N$ and $Q$ are integers. * $1 \leq N, Q \leq 3 \times 10^5$ * $S$ is a string of length $N$ consisting of lowercase English letters. * $l_i$ and $r_i$ are integers. * $1 \leq l_i \leq r_i \leq N$ ## Input The input is given from Standard Input in the following format: $N$ $Q$ $S$ $l_1$ $r_1$ $l_2$ $r_2$ $\vdots$ $l_Q$ $r_Q$ [samples]

Samples

Input #1

11 4
mississippi
3 9
4 10
4 6
7 7

Output #1

2
2
0
0

The answers to the four queries are as follows.

*   For the first query, $S_3S_4\ldots S_9 = $ `ssissip` has two places where the same lowercase English letter occurs twice in a row: $S_3S_4 = $ `ss` and $S_6S_7 = $ `ss`.
*   For the second query, $S_4S_5\ldots S_{10} = $ `sissipp` has two places where the same lowercase English letter occurs twice in a row: $S_6S_7 = $ `ss` and $S_9S_{10} = $ `pp`.
*   For the third query, $S_4S_5S_6 = $ `sis` has zero places where the same lowercase English letter occurs twice in a row.
*   For the fourth query, $S_7 = $ `s` has zero places where the same lowercase English letter occurs twice in a row.

Input #2

5 1
aaaaa
1 5

Output #2

4

$S_1S_2\ldots S_5 = $ `aaaaa` has four places where the same lowercase English letter occurs twice in a row: $S_1S_2 = $ `aa`, $S_2S_3 = $ `aa`, $S_3S_4 = $ `aa`, and $S_4S_5 = $ `aa`.

API Response (JSON)

{
  "problem": {
    "name": "Consecutive",
    "description": {
      "content": "You are given a string $S = S_1S_2\\ldots S_N$ of length $N$ consisting of lowercase English letters. Additionally, you are given $Q$ queries about the string $S$. For $i = 1, 2, \\ldots, Q$, the $i$\\-t",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc328_c"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "You are given a string $S = S_1S_2\\ldots S_N$ of length $N$ consisting of lowercase English letters.\nAdditionally, you are given $Q$ queries about the string $S$. For $i = 1, 2, \\ldots, Q$, the $i$\\-t...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

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