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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
#define SE second
#define vi vector<int>
#define pb push_back
#define pi pair<int,int>
#define mp make_pair
#define LL long long
#define LI long int
#define LLI long long int
#define REP(i,a,b) for(long long i=a;i<b;i++)
#define PER(i,a,b) for(int i=b-1;i>=a;i--)
#define YES(i) cout<<(i?"YES":"NO")<<endl
#define Yes(i) cout<<(i?"Yes":"No")<<endl
#define POS(i) cout<<(i?"POSSIBLE":"IMPOSSIBLE")<<endl

using namespace std;
template< unsigned mod >
struct RollingHash {
    vector< unsigned > hashed, power;

    inline unsigned mul(unsigned a, unsigned b) const {
        unsigned long long x = (unsigned long long) a * b;
        unsigned xh = (unsigned) (x >> 32), xl = (unsigned) x, d, m;
        asm("divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (mod));
        return m;
    }

    RollingHash(const string &s, unsigned base = 10007) {
        int sz = (int) s.size();
        hashed.assign(sz + 1, 0);
        power.assign(sz + 1, 0);
        power[0] = 1;
        for(int i = 0; i < sz; i++) {
            power[i + 1] = mul(power[i], base);
            hashed[i + 1] = mul(hashed[i], base) + s[i];
            if(hashed[i + 1] >= mod) hashed[i + 1] -= mod;
        }
    }

    unsigned get(int l, int r) const {
        unsigned ret = hashed[r] + mod - mul(hashed[l], power[r - l]);
        if(ret >= mod) ret -= mod;
        return ret;
    }

    unsigned connect(unsigned h1, int h2, int h2len) const {
        unsigned ret = mul(h1, power[h2len]) + h2;
        if(ret >= mod) ret -= mod;
        return ret;
    }

    int LCP(const RollingHash< mod > &b, int l1, int r1, int l2, int r2) {
        int len = min(r1 - l1, r2 - l2);
        int low = -1, high = len + 1;
        while(high - low > 1) {
            int mid = (low + high) / 2;
            if(get(l1, l1 + mid) == b.get(l2, l2 + mid)) low = mid;
            else high = mid;
        }
        return (low);
    }
};
//using RH = RollingHash< 1000000007 >;

int main() {
    string S,T,P="AC";
    LL q,ruiseki=0;
    cin >>T>>q>>T;
    int a[100001];
    RollingHash<1000000007> rh(T), rh2(P);
    for (int i = 0; i + P.size() <= T.size(); i++) {
            if (rh.get(i, i + P.size()) == rh2.get(0, P.size())) {
               ruiseki++;
            }
            a[i+1]+=ruiseki;
            //cout<<a[i+1]<<endl;
    }
    REP(i,0,q){
        LL r,l;
        cin>>r>>l;
        l-r<2?cout<<0<<endl:cout<<a[l-1]-a[r-1]<<endl;
    }
}