#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
map<char, int> mp;
string a, b;
void init(std::string _a, std::string _b) {
a = _a;
b = _b;
mp['A'] = 0;
mp['T'] = 1;
mp['C'] = 2;
}
int get_distance(int x, int y) {
vector<vector<int>> d1(3), d2(3);
for (int i = x; i <= y; ++i) {
d1[mp[a[i]]].push_back(i);
d2[mp[b[i]]].push_back(i);
}
int res = 0;
for (int i = 0; i < 3; ++i) {
auto& v1 = d1[i];
auto& v2 = d2[i];
if (v1.size() != v2.size()) return -1;
for (int j = 0; j < (int)v1.size(); ++j) {
res += abs(v1[j] - v2[j]);
}
}
assert(res % 2 == 0);
return res / 2;
}
