//#include "grader.cpp"
#include "dna.h"
#include <bits/stdc++.h>
#define pb push_back
using namespace std;
string str1, str2;
int n;
int tree[6][400000];
int get(char a, char b){
if(a == 'A' && b == 'C')
return 0;
else if(a == 'A' && b == 'T')
return 1;
else if(a == 'C' && b == 'T')
return 2;
else if(a == 'C' && b == 'A')
return 3;
else if(a == 'T' && b == 'A')
return 4;
else
return 5;
}
void build(int node, int l, int r){
if(l == r){
tree[get(str1[l], str2[l])][node] = 1;
}
else{
int mid = (l + r) / 2;
build(node * 2, l, mid);
build(node * 2 + 1, mid + 1, r);
tree[0][node] = tree[0][node * 2] + tree[0][node * 2 + 1];
tree[1][node] = tree[1][node * 2] + tree[1][node * 2 + 1];
tree[2][node] = tree[2][node * 2] + tree[2][node * 2 + 1];
tree[3][node] = tree[3][node * 2] + tree[3][node * 2 + 1];
tree[4][node] = tree[4][node * 2] + tree[4][node * 2 + 1];
tree[5][node] = tree[5][node * 2] + tree[5][node * 2 + 1];
}
}
int query(int node, int l, int r, int L, int R, int id){
if(r < L || l > R)
return 0;
if(L <= l && r <= R)
return tree[id][node];
int mid = (l + r) / 2;
int left = query(node * 2, l, mid, L, R, id);
int right = query(node * 2 + 1, mid + 1, r, L, R, id);
return left + right;
}
void init(string a, string b){
n = a.size();
str1 = a;
str2 = b;
memset(tree, 0, sizeof(tree));
build(1, 0, n-1);
}
int get_distance(int x, int y) {
int l = x, r = y;
int calc[6];
for(int i = 0; i < 6; i++){
calc[i] = query(1, 0, n-1, l, r, i);
//cout<<calc[i]<<endl;
}
int ans = 0;
int sm = min(calc[0], calc[3]);
ans += sm;
calc[0] -= sm;
calc[3] -= sm;
sm = min(calc[1], calc[4]);
ans += sm;
calc[1] -= sm;
calc[4] -= sm;
sm = min(calc[2],calc[5]);
ans += sm;
calc[2] -= sm;
calc[5] -= sm;
bool pos = true;
if(calc[0] == 0 && calc[2] == 0 && calc[4] == 0){
if(calc[1] == calc[3] && calc[3] == calc[5]){
ans += calc[1] * 2;
}
else
pos = false;
}
else if(calc[1] == 0 && calc[3] == 0 && calc[5] == 0){
if(calc[0] == calc[2] && calc[2] == calc[4]){
ans += calc[0] * 2;
}
else
pos = false;
}
else
pos = false;
if(!pos)
return -1;
else
return ans;
}
