#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
int AC[100005];
int CA[100005];
int AT[100005];
int TA[100005];
int TC[100005];
int CT[100005];
void init(std::string a, std::string b) {
AC[0] = 0;
CA[0] = 0;
AT[0] = 0;
TA[0] = 0;
TC[0] = 0;
CT[0] = 0;
for(int i = 0; i < (int)a.size(); ++i){
if(i > 0){
AC[i] = AC[i-1];
CA[i] = CA[i-1];
AT[i] = AT[i-1];
TA[i] = TA[i-1];
TC[i] = TC[i-1];
CT[i] = CT[i-1];
}
if(a[i] == b[i])continue;
if(a[i] == 'A' && b[i] == 'C'){
AC[i]++;
}
if(a[i] == 'A' && b[i] == 'T'){
AT[i]++;
}
if(a[i] == 'T' && b[i] == 'A'){
TA[i]++;
}
if(a[i] == 'C' && b[i] == 'A'){
CA[i]++;
}
if(a[i] == 'C' && b[i] == 'T'){
CT[i]++;
}
if(a[i] == 'T' && b[i] == 'C'){
TC[i]++;
}
}
}
int get_distance(int x, int y) {
int ac = AC[y];
int ca = CA[y];
int at = AT[y];
int ta = TA[y];
int tc = TC[y];
int ct = CT[y];
if(x > 0){
ac -= AC[x-1];
ca -= CA[x-1];
at -= AT[x-1];
ta -= TA[x-1];
tc -= TC[x-1];
ct -= CT[x-1];
}
int ans = 0;
if(ac > ca){
swap(ca, ac);
}
if(at > ta){
swap(at, ta);
}
if(tc > ct){
swap(tc, ct);
}
ans += ac;
ans += at;
ans += tc;
ca -= ac;
ta -= at;
ct -= tc;
if(ct == ta && ct == ca){
ans += 2 * ct;
return ans;
}else{
return -1;
}
}
