#include <bits/stdc++.h>
using namespace std;
template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl
using ll = long long;
const int maxn = 1e6 + 5;
bool isprime(ll x) {
if (x<=1) return false;
for (ll i=2; i*i<=x; i++) {
if (x%i==0) return false;
}
return true;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
assert(isprime(41));
ll a,b;
cin>>a>>b;
//0->2->1->0->2->0.. mod3
map<ll,vector<ll>> g;
vector<ll> tmp = {a-2,a,a+2,b-2,b,b+2,2};
vector<ll> nodes;
for (ll x: tmp) {
if (isprime(x)) {
nodes.push_back(x);
}
}
for (int i=0; i<(int)nodes.size(); i++) {
for (int j=i+1; j<(int)nodes.size(); j++) {
ll x = nodes[i];
ll y = nodes[j];
if (isprime(abs(x-y))) {
g[x].push_back(y);
g[y].push_back(x);
}
}
}
map<ll,ll> par;
queue<ll> qq;
qq.push(a);
while (qq.size()) {
ll at = qq.front();
qq.pop();
for (ll to: g[at]) {
if (!par.count(to)) {
par[to] = at;
qq.push(to);
}
}
}
if (!par.count(b)) out(-1);
vector<ll> path;
while (b != a) {
path.push_back(b);
b = par[b];
}
path.push_back(a);
cout<<path.size()<<"\n";
while (path.size()) {
cout<<path.back()<<" ";
path.pop_back();
}
cout<<endl;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
472 ms |
492 KB |
Output is correct |
2 |
Correct |
328 ms |
392 KB |
Output is correct |
3 |
Correct |
574 ms |
492 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
463 ms |
492 KB |
Output is correct |
2 |
Correct |
295 ms |
364 KB |
Output is correct |
3 |
Correct |
411 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
514 ms |
492 KB |
Output is correct |
2 |
Correct |
344 ms |
620 KB |
Output is correct |
3 |
Correct |
378 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
376 ms |
388 KB |
Output is correct |
2 |
Correct |
239 ms |
364 KB |
Output is correct |
3 |
Correct |
135 ms |
364 KB |
Output is correct |