#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
int n;
string A;
string B;
void init(string a, string b){
n = (int)a.size();
A = a;
B = b;
}
int get_distance(int x, int y){
map<char, int> mp;
map<char, int> mp2;
string C = "";
string D = "";
for(int i = x; i <= y; i++){
mp[A[i]]++;
mp2[B[i]]++;
C += A[i];
D += B[i];
}
if(mp['A'] == mp2['A'] && mp['C'] == mp2['C'] && mp['T'] == mp2['T']){
int m = y - x + 1;
int cnt = 0;
for(int i = 0; i < m; i++){
if(C[i] == D[i]){
continue;
}
else{
for(int j = i + 1; j < m; j++){
if(D[i] == C[j]){
swap(C[i], C[j]);
cnt++;
break;
}
}
}
}
return cnt;
}
else{
return -1;
}
}
