Codeforce - Ilya and queries

#include<bits/stdc++.h>
using namespace std;
#define fast()(ios_base::sync_with_stdio(false),cin.tie(NULL));
int main()
{
    string a;
    getline(cin,a);
    //cin.ignore();
    int q,i,n=a.size(),ara[n+2];
    ara[0]=0;
    for(i=1;i<n;i++)
    {
        if(a[i]==a[i-1])ara[i]=ara[i-1]+1;
        else ara[i]=ara[i-1];
    }
    scanf("%d",&q);
    while(q--)
    {
        int x,y;
        scanf("%d %d",&x,&y);
        printf("%d\n",ara[y-1]-ara[x-1]);
    }
    return 0;
}