#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
vector<int64_t> T1;
vector<int64_t> T2;
vector<int64_t> A1;
vector<int64_t> A2;
vector<int64_t> C1;
vector<int64_t> C2;
vector<int64_t> same;
void init(std::string a, std::string b) {
int64_t len = a.size();
T1.resize(len+1);
T2.resize(len+1);
A1.resize(len+1);
A2.resize(len+1);
C1.resize(len+1);
C2.resize(len+1);
same.resize(len+1);
int64_t currA1 = 0;
int64_t currT1 = 0;
int64_t currA2 = 0;
int64_t currT2 = 0;
int64_t currC1 = 0;
int64_t currC2 = 0;
int64_t currsame = 0;
for(int i = 0; i < len; i++){
if(a[i] == 'A'){
currA1++;
}else if(a[i] == 'T'){
currT1++;
}else if(a[i] == 'C'){
currC1++;
}
if(b[i] == 'A'){
currA2++;
}else if(b[i] == 'T'){
currT2++;
}else if(b[i] == 'C'){
currC2++;
}
if(a[i] == b[i]){
currsame++;
}
A1[i+1] = currA1;
T1[i+1] = currT1;
A2[i+1] = currA2;
T2[i+1] = currT2;
C1[i+1] = currC1;
C2[i+1] = currC2;
same[i+1] = currsame;
}
}
int get_distance(int x, int y) {
int64_t a1 = A1[y+1] - A1[x];
int64_t t1 = T1[y+1] - T1[x];
int64_t c1 = C1[y+1] - C1[x];
int64_t a2 = A2[y+1] - A2[x];
int64_t t2 = T2[y+1] - T2[x];
int64_t c2 = C2[y+1] - C2[x];
int64_t s = same[y+1] - same[x];
// cout << s << endl;
if(t1 != t2 || a1 != a2 || c1 != c2){
// cout << t1 << " " << t2 << endl;
// cout << a1 << " " << a2 << endl;
// cout << c1 << " " << c2 << endl;
return -1;
}
return ceil((((y-x)+1 ) - s )/ 2.0);
}
