#include <bits/stdc++.h>
#include "dna.h"
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <long double, pii> muchie;
const ll NMAX = 100001;
const ll VMAX = 1000001;
const ll INF = (1LL << 60);
const ll MOD = 1000000007;
const ll BLOCK = 1000000;
const ll nr_of_bits = 16;
struct mat{
int wrong[3][3];
void clear(){
for(int i = 0; i < 3; i++){
for(int j = 0; j < 3; j++)
wrong[i][j] = 0;
}
}
};
class AINT {
public:
mat aint[4 * NMAX];
mat combine(mat a, mat b) {
mat sol;
sol.clear();
for(int i = 0; i < 3; i++) {
for(int j = 0; j < 3; j++) {
sol.wrong[i][j] = a.wrong[i][j] + b.wrong[i][j];
}
}
return sol;
}
void update(int node, int st, int dr, int poz, int a, int b) {
aint[node].wrong[a][b]++;
if(st == dr) {
return;
}
int mid = (st + dr) / 2;
if(poz <= mid)
update(node * 2, st, mid, poz, a, b);
else
update(node * 2 + 1, mid + 1, dr, poz, a, b);
}
mat query(int node, int st, int dr, int a, int b) {
if(a <= st && dr <= b) {
return aint[node];
}
int mid = (st + dr) / 2;
mat sol;
sol.clear();
if(a <= mid)
sol = combine(sol, query(node * 2, st, mid, a, b));
if(b > mid)
sol = combine(sol, query(node * 2 + 1, mid + 1, dr, a, b));
return sol;
}
}st;
int n;
int getCode(char c){
if(c == 'A')
return 0;
else if(c == 'C')
return 1;
return 2;
}
void init(std::string a, std::string b) {
n = a.size();
for(int i = 0; i < 4 * NMAX; i++)
st.aint[i].clear();
for(int i = 0; i < a.size(); i++){
int codA = getCode(a[i]);
int codB = getCode(b[i]);
if(codA != codB)
st.update(1, 1, n, i + 1, codA, codB);
}
}
int get_distance(int x, int y) {
x++;
y++;
mat my = st.query(1, 1, n, x, y);
for(int i = 0; i < 3; i++){
int s = 0;
for(int j = 0; j < 3; j++){
s += my.wrong[i][j];
}
for(int j = 0; j < 3; j++){
s -= my.wrong[j][i];
}
if(s != 0){
return -1;
}
}
int cnt = 0;
for(int i = 0; i < 3; i++){
for(int j = 0; j < 3; j++){
int minim = min(my.wrong[j][i], my.wrong[i][j]);
my.wrong[j][i] -= minim;
my.wrong[i][j] -= minim;
cnt += minim;
}
}
int s = 0;
for(int i = 0; i < 3; i++){
for(int j = 0; j < 3; j++){
s += my.wrong[i][j];
}
}
s /= 3;
s *= 2;
cnt += s;
return cnt;
}
