#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
string a,b;
int n;
vector<int> pa1,pa2,pc1,pc2,pt1,pt2,AC,CA,AT,TA,CT,TC;
void init(std::string aa, std::string bb) {
a=aa;b=bb;
n=a.size();
pa1.resize(n+1,0);pa2.resize(n+1,0);
pc1.resize(n+1,0);pc2.resize(n+1,0);
pt1.resize(n+1,0);pt2.resize(n+1,0);
for(int i=0; i<n; i++){
pa1[i+1]=pa1[i];pc1[i+1]=pc1[i];pt1[i+1]=pt1[i];
if(a[i]=='A')
pa1[i+1]++;
if(a[i]=='C')
pc1[i+1]++;
if(a[i]=='T')
pt1[i+1]++;
}
for(int i=0; i<n; i++){
pa2[i+1]=pa2[i];pc2[i+1]=pc2[i];pt2[i+1]=pt2[i];
if(b[i]=='A')
pa2[i+1]++;
if(b[i]=='C')
pc2[i+1]++;
if(b[i]=='T')
pt2[i+1]++;
}
AC.resize(n+1,0);CA.resize(n+1,0);
AT.resize(n+1,0);TA.resize(n+1,0);
CT.resize(n+1,0);TC.resize(n+1,0);
for(int i=0; i<n; i++){
AC[i+1]=AC[i];CA[i+1]=CA[i];AT[i+1]=AT[i];TA[i+1]=TA[i];CT[i+1]=CT[i];TC[i+1]=TC[i];
if(a[i]=='A'&&b[i]=='C')
AC[i+1]++;
if(a[i]=='A'&&b[i]=='T')
AT[i+1]++;
if(a[i]=='T'&&b[i]=='C')
TC[i+1]++;
if(a[i]=='T'&&b[i]=='A')
TA[i+1]++;
if(a[i]=='C'&&b[i]=='T')
CT[i+1]++;
if(a[i]=='C'&&b[i]=='A')
CA[i+1]++;
}
}
int get_distance(int x, int y) {
y++;
if(pa1[y]-pa1[x]!=pa2[y]-pa2[x])
return -1;
if(pc1[y]-pc1[x]!=pc2[y]-pc2[x])
return -1;
if(pt1[y]-pt1[x]!=pt2[y]-pt2[x])
return -1;
int A_C=AC[y]-AC[x];
int A_T=AT[y]-AT[x];
int C_A=CA[y]-CA[x];
int C_T=CT[y]-CT[x];
int T_A=TA[y]-TA[x];
int T_C=TC[y]-TC[x];
int rez=0,mini;
mini=min(A_C,C_A);
rez+=mini;
A_C-=mini;
C_A-=mini;
mini=min(A_T,T_A);
rez+=mini;
A_T-=mini;
T_A-=mini;
mini=min(C_T,T_C);
rez+=mini;
C_T-=mini;
T_C-=mini;
rez+=((A_C+A_T+C_A+C_T+T_A+T_C)/3)*2;
return rez;
}
