#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
string s, t;
vector<int> afix;
vector<int> bfix;
vector<int> dp0;
string aa = "A";
string bb = "T";
int l = 0;
void init(string a, string b) {
s = a;
t = b;
l = a.length();
vector<int> af(a.length(), 0);
vector<int> bf(b.length(), 0);
vector<int> dp(a.length(), 0);
if(a[0] != b[0]){
dp[0] = 1;
}
if(a[0] == aa[0]){
af[0] = 1;
} else {
//af[0] = -1;
}
if(b[0] == aa[0]){
bf[0] = 1;
} else {
//bf[0] = -1;
}
for(int i = 1; i < l; i ++){
if(a[i] != b[i]){
dp[i] = dp[i-1] + 1;
} else {
dp[i] = dp[i-1];
}
if(a[i] == aa[0]){
af[i] = af[i-1] + 1;
} else {
af[i] = af[i-1];
}
if(b[i] == aa[0]){
bf[i] = bf[i-1] + 1;
} else {
bf[i] = bf[i-1];
}
}
dp0 = dp;
afix = af;
bfix = bf;
}
int get_distance(int x, int y) {
if(x == 0){
if(afix[y] == bfix[y]){
return dp0[y] / 2;
} else {
return -1;
}
} else {
if(afix[y] - afix[x-1] == bfix[y] - bfix[x-1]){
return (dp0[y] - dp0[x-1]) / 2;
} else {
return -1;
}
}
}
/*
7 3
ATTATAT
TATATTA
0 6
0 1
3 6
*/
