#include <bits/stdc++.h>
using namespace std;
using ll = long long;
map<int, ll> compress;
vector<ll> primes;
vector<int> adj[10];
bool visited[10], found = 0;
ll A, B;
bool isPrime(ll n) {
if (n < 2) return false;
for(ll i = 2; i*i <= n; i++) {
if (n % i == 0) {
return false;
}
}
return true;
}
void dfs(int v, vector<int> path) {
path.push_back(v);
if (compress[v] == B) {
if (found) break;
found = 1;
cout << path.size() << "\n";
for(int i : path) {
cout << compress[i] << " ";
}
cout << "\n";
return;
}
visited[v] = true;
for(int u : adj[v]) {
if (!visited[u]) {
dfs(u, path);
}
}
path.pop_back();
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> A >> B;
primes.push_back(A);
primes.push_back(B);
if (A != 2 && B != 2) primes.push_back(2);
if (isPrime(A-2) && A-2 != B) {
primes.push_back(A-2);
}
if (isPrime(A+2) && A+2 != B) {
primes.push_back(A+2);
}
if (isPrime(B-2) && B-2 != A) {
primes.push_back(B-2);
}
if (isPrime(B+2) && B+2 != A) {
primes.push_back(B+2);
}
int n = primes.size();
int id = 0, start = 0;
for(ll i : primes) {
if (i == A) start = id;
compress[id++] = i;
}
for(int i = 0; i < n-1; i++) {
for(int j = i+1; j < n; j++) {
if (isPrime(abs(compress[i] - compress[j]))) {
adj[i].push_back(j);
adj[j].push_back(i);
}
}
}
vector<int> path;
dfs(start, path);
if (!found) {
cout << -1;
}
// for(int i = 0; i < n; i++) {
// cout << compress[i] << ":\n";
// for(int u : adj[i]) {
// cout << compress[u] << " ";
// }
// cout << "\n";
// }
return 0;
}
//~ check for overflows
Compilation message
lutrija.cpp: In function 'void dfs(int, std::vector<int>)':
lutrija.cpp:23:20: error: break statement not within loop or switch
23 | if (found) break;
| ^~~~~
