#include "dna.h"
#include <bits/stdc++.h>
#define MAXN 100001
int at[MAXN];
int ac[MAXN];
int ta[MAXN];
int tc[MAXN];
int ca[MAXN];
int ct[MAXN];
void init(std::string a, std::string b) {
at[0]=0;
ac[0]=0;
ta[0]=0;
tc[0]=0;
ca[0]=0;
ct[0]=0;
int n=a.size();
for(int i=0;i<n;i++){
at[i+1]=at[i];
ac[i+1]=ac[i];
ta[i+1]=ta[i];
tc[i+1]=tc[i];
ca[i+1]=ca[i];
ct[i+1]=ct[i];
at[i+1]+=(a[i]=='A' && b[i]=='T');
ac[i+1]+=(a[i]=='A' && b[i]=='C');
ta[i+1]+=(a[i]=='T' && b[i]=='A');
tc[i+1]+=(a[i]=='T' && b[i]=='C');
ca[i+1]+=(a[i]=='C' && b[i]=='A');
ct[i+1]+=(a[i]=='C' && b[i]=='T');
}
}
int get_distance(int x, int y) {
int a,b,n,m,o,p,q,r;
o=0;
a=at[x+1]-at[y];
n=ac[x+1]-ac[y];
b=ta[x+1]-ta[y];
p=tc[x+1]-tc[y];
m=ca[x+1]-ca[y];
q=ct[x+1]-ct[y];
r=std::min(a,b);
a-=r;
b-=r;
o+=r;
r=std::min(n,m);
n-=r;
m-=r;
o+=r;
r=std::min(p,q);
p-=r;
q-=r;
o+=r;
if(std::max(a,b)==std::max(n,m) && std::max(n,m)==std::max(p,q))
return o+std::max(a,b)*2;
return -1;
}
