#include "dna.h"
#include "bits/stdc++.h"
using namespace std;
const int N = 1e5 + 6;
int pa[N][3], pb[N][3], p[N];
string a_, b_;
map < char , int > ch;
vector < char > letters{'A', 'C', 'T'};
void init(string a, string b){
int n = (int)a.size();
a = '#' + a;
b = '#' + b;
a_ = a, b_ = b;
ch['A'] = 0, ch['C'] = 1, ch['T'] = 2;
for(int i = 1; i <= n; i++){
pa[i][ch[a[i]]]++;
pb[i][ch[b[i]]]++;
for(int c = 0; c < 3; c++){
pa[i][c] += pa[i - 1][c];
pb[i][c] += pb[i - 1][c];
}
}
}
int get_distance(int x, int y){
x++, y++;
string a = a_, b = b_;
for(int i = 0; i < 3; i++){
if(pb[y][i] - pb[x - 1][i] != pa[y][i] - pa[x - 1][i])
return -1;
}
map < pair < char, char >, vector < int > > s;
for(int i = x; i <= y; i++){
if(a[i] != b[i])
s[{a[i], b[i]}].push_back(i);
}
int cnt = 0;
while(1){
int ok = 0;
for(auto i : letters){
for(auto j : letters){
if(s[{i, j}].size() == 0){
ok++;
continue;
}
// cout << i << ' ' << j << endl;
if(s[{j, i}].size() != 0){
s[{i, j}].pop_back();
s[{j, i}].pop_back();
}
else {
for(auto k : letters){
if(s[{j, k}].size() != 0){
s[{i, k}].push_back(s[{i, j}].back());
s[{i, j}].pop_back();
s[{j, k}].pop_back();
break;
}
}
}
cnt++;
}
}
if(ok == 9)break;
}
return cnt;
}
