#include "dna.h"
#include <map>
#include <vector>
#include <iostream>
using namespace std;
map<string, vector<int>> ps;
int n;
void init(std::string a, std::string b) {
n = a.size();
map<string, int> prev;
for (int i = 0; i < n; i++) {
ps["AT"].push_back(prev["AT"]);
ps["AC"].push_back(prev["AC"]);
ps["CA"].push_back(prev["CA"]);
ps["CT"].push_back(prev["CT"]);
ps["TA"].push_back(prev["TA"]);
ps["TC"].push_back(prev["TC"]);
if (a[i] == b[i])
continue;
string s = (string)a.substr(i, 1);
s += b[i];
int temp = ps[s].back();
ps[s].pop_back();
ps[s].push_back(temp+1);
prev["AT"] = ps["AT"].back();
prev["AC"] = ps["AC"].back();
prev["CA"] = ps["CA"].back();
prev["CT"] = ps["CT"].back();
prev["TA"] = ps["TA"].back();
prev["TC"] = ps["TC"].back();
}
}
int get_distance(int x, int y) {
map<string, int> cnt;
if (x > 0) {
cnt["AT"] = ps["AT"][y]-ps["AT"][x-1];
cnt["AC"] = ps["AC"][y]-ps["AC"][x-1];
cnt["CA"] = ps["CA"][y]-ps["CA"][x-1];
cnt["CT"] = ps["CT"][y]-ps["CT"][x-1];
cnt["TA"] = ps["TA"][y]-ps["TA"][x-1];
cnt["TC"] = ps["TC"][y]-ps["TC"][x-1];
}
else {
cnt["AT"] = ps["AT"][y];
cnt["AC"] = ps["AC"][y];
cnt["CA"] = ps["CA"][y];
cnt["CT"] = ps["CT"][y];
cnt["TA"] = ps["TA"][y];
cnt["TC"] = ps["TC"][y];
}
int ans = 0;
int t = min(cnt["TA"], cnt["AT"]);
ans += t;
cnt["TA"] -= t, cnt["AT"] -= t;
t = min(cnt["AC"], cnt["CA"]);
ans += t;
cnt["AC"] -= t, cnt["CA"] -= t;
t = min(cnt["CT"], cnt["TC"]);
ans += t;
cnt["CT"] -= t, cnt["TC"] -= t;
t = min(min(cnt["AT"], cnt["TC"]), cnt["CA"]);
ans += 2*t;
cnt["AT"] -= t, cnt["TC"] -= t, cnt["CA"] -= t;
t = min(min(cnt["TA"], cnt["AC"]), cnt["CT"]);
ans += 2*t;
cnt["TA"] -= t, cnt["AC"] -= t, cnt["CT"] -= t;
if (cnt["AT"] || cnt["TA"] || cnt["AC"] || cnt["CA"] || cnt["TC"] || cnt["CT"])
ans = -1;
return ans;
}
