Problem:
Score : 300 points

Problem Statement

You are given a string S of length N consisting of A, C, G and T. Answer the following Q queries:

Query i (1 \leq i \leq Q): You will be given integers l_i and r_i (1 \leq l_i < r_i \leq N). Consider the substring of S starting at index l_i and ending at index r_i (both inclusive). In this string, how many times does AC occurs as a substring?

Notes

A substring of a string T is a string obtained by removing zero or more characters from the beginning and the end of T.

For example, the substrings of ATCODER include TCO, AT, CODER, ATCODER and (the empty string), but not AC.

Constraints

2 \leq N \leq 10^5

1 \leq Q \leq 10^5

S is a string of length N.

Each character in S is A, C, G or T.

1 \leq l_i < r_i \leq N

Input

Input is given from Standard Input in the following format:

N Q
S
l_1 r_1
:
l_Q r_Q

Output

Print Q lines. The i-th line should contain the answer to the i-th query.

Sample Input 1

8 3
ACACTACG
3 7
2 3
1 8

Sample Output 1

2
0
3

Query 1: the substring of S starting at index 3 and ending at index 7 is ACTAC. In this string, AC occurs twice as a substring.

Query 2: the substring of S starting at index 2 and ending at index 3 is CA. In this string, AC occurs zero times as a substring.

Query 3: the substring of S starting at index 1 and ending at index 8 is ACACTACG. In this string, AC occurs three times as a substring.

Solution in Java (OpenJDK 11.0.6) (judge verdict: Time Limit Exceeded)

import java.util.ArrayList;
import java.util.Scanner;


public class Main {

    public static String Y = "Yes";
    public static String N = "No";
    public static long MOD = (long) (Math.pow(10, 9) + 7);
    public static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {

        int n = ni(); // 長さ
        int q = ni(); // 問い
        String s = n();

        ArrayList<Integer> acindex = new ArrayList<>();

        // ACの最初のAのindexを取得
        for (int i = 0; i < n - 1; i++) {
            char a = s.charAt(i);
            char c = s.charAt(i + 1);
            if (a == 'A' && c == 'C') {
                acindex.add(i);
            }
        }

        for (int i = 0; i < q; i++) {
            int l = ni();
            int r = ni();
            int count = 0;
            for (int j = l - 1; j < r - 1; j++) {
                if (acindex.contains(j)) {
                    count++;
                }
            }
            out(count);
        }

    }

    /*
     * 以下メソッド集
     */

    static int ketasuu(int n) {

        String str = "" + n;
        return str.length();
    }

    static int abcount(String str) {

        int count = 0;
        int len = str.length();
        for (int i = 0; i < len - 1; i++) {
            if ("AB".equals(str.substring(i, i + "AB".length()))) {
                count++;
            }
        }
        return count;
    }

    static int ni() {

        return sc.nextInt();
    }

    static long nl() {

        return sc.nextLong();
    }

    static double nd() {

        return sc.nextDouble();
    }

    static String n() {

        return sc.next();
    }

    static char[] nc() {

        return sc.next().toCharArray();
    }

    static int kaijo(int n) {

        if (n == 0 || n == 1) {
            return 1;
        } else {
            return n * kaijo(n - 1);
        }
    }

    static int fib(int n) {

        return (n == 1 || n == 0) ? n : fib(n - 2) + fib(n - 1);
    }

    static long lcm(long m, long n) {

        return m * n / gcd(m, n);
    }

    static int lcm(int m, int n) {

        return m * n / gcd(m, n);
    }

    static long gcd(long a, long b) {

        return (b == 0) ? a : gcd(b, a % b);
    }

    static int gcd(int a, int b) {

        return (b == 0) ? a : gcd(b, a % b);
    }

    static void out(String info) {

        System.out.println(info);
    }

    static void out(int info) {

        System.out.println(info);
    }

    static void out(double info) {

        System.out.println(info);
    }

    static void out(long info) {

        System.out.println(info);
    }

    static void out(char info) {

        System.out.println(info);
    }

    static void out(Object obj) {

        System.out.println(obj.toString());
    }

    static void outn(String info) {

        System.out.print(info);
    }

    static void outn(int info) {

        System.out.print(info);
    }

    static void outn(double info) {

        System.out.print(info);
    }

    static void outn(long info) {

        System.out.print(info);
    }

    static void outn(char info) {

        System.out.print(info);
    }

    static double max(double d, double e) {

        return Math.max(d, e);
    }

    static long max(long a, long b) {

        return Math.max(a, b);
    }

    static double min(double d, double e) {

        return Math.min(d, e);
    }

    static long min(long a, long b) {

        return Math.min(a, b);
    }
}


class XY {

    int h;
    int c;

    XY(int h, int c) {
        this.h = h;
        this.c = c;
    }
}