// SUBTASK 1 -> 3
#include <bits/stdc++.h>
#include "dna.h"
//#include "grader.cpp"
using namespace std;
string a, b;
vector <int> pref;
void init(string A, string B)
{
a = A;
b = B;
int n = a.size();
pref.clear();
pref.resize(n);
for (int i = 0; i < n; i++)
{
if (a[i] != b[i])
{
pref[i] = i > 0 ? pref[i - 1] + 1 : 1;
}
else pref[i] = i > 0 ? pref[i - 1] : 0;
}
}
bool validate(int x, int y)
{
string s1, s2;
for (int i = x; i <= y; i++)
{
s1 += a[i];
s2 += b[i];
}
sort(s1.begin(), s1.end());
sort(s2.begin(), s2.end());
return (s1 == s2);
}
int get_distance(int x, int y)
{
if (!validate(x, y)) return -1;
int br = 0;
if (x > 0) br = pref[y] - pref[x - 1];
else br = pref[y];
//cout << br << endl;
return br / 2;
}
/*
6 3
ATACAT
ACTATA
1 3
4 5
3 5
2
1
-1
*/
