Problem10377--ABC328 —— C - Consecutive

10377: ABC328 —— C - Consecutive

[Creator : ]
Time Limit : 1.000 sec  Memory Limit : 512 MiB

Description

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.

Input

The input is given from Standard Input in the following format:

```
$N$ $Q$
$S$
$l_1$ $r_1$
$l_2$ $r_2$
$\vdots$
$l_Q$ $r_Q$
```

Output

Print $Q$ lines. For $i = 1, 2, \ldots, Q$, the $i$-th line should contain the answer to the $i$-th query.

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.
-   $1 \leq l_i \leq r_i \leq N$

Sample 1 Input

11 4
mississippi
3 9
4 10
4 6
7 7

Sample 1 Output

2
2
0
0

The answers to the four queries are as follows.

  • For the first query, $S_3S_4…S_9$= 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, $S_4S_5…S_{10}$= 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.

Sample 2 Input

5 1
aaaaa
1 5

Sample 2 Output

4
$S_1S_2…S_5$= 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.

Source/Category