#include "dna.h"
#include <vector>
#include <array>
#include <algorithm>
#define all(a) a.begin(), a.end()
using namespace std;
vector<int> a, b;
void init(std::string _a, std::string _b) {
a.resize(_a.size());
b.resize(_b.size());
for (int i = 0; i < (int) _a.size(); ++i) {
if (_a[i] == 'A') {
a[i] = 0;
} else if (_a[i] == 'T') {
a[i] = 1;
} else {
a[i] = 2;
}
if (_b[i] == 'A') {
b[i] = 0;
} else if (_b[i] == 'T') {
b[i] = 1;
} else {
b[i] = 2;
}
}
}
int get_distance(int x, int y) {
array<int, 3> c1, c2;
int sum = 0;
fill(all(c1), 0);
fill(all(c2), 0);
for (int i = x; i <= y; ++i) {
if (a[i] != b[i]) {
++c1[a[i]];
++c2[b[i]];
++sum;
}
}
if (c1 != c2) {
return -1;
} else {
return max(*max_element(all(c1)), (sum + 1) / 2);
}
return 0;
}
