소수 최소 공배수

#include <iostream> #include <algorithm> #include <cmath> #include <stack> using namespace std; bool isPrime(int a) { int max_idx = sqrt(a); bool isDivided = false; for (int i = 2; i <= max_idx; i++) { if (a % i == 0) { isDivided = true; break ; } } if (isDivided) return (false); return (true); } long long gcd(long long a, long long b) { if (b == 0) return (a); return (gcd(b, a % b)); } long long lcm(long long a, long long b) { return (a * b / gcd(a, b)); } int main(void) { int n; int input; stack<long long> s; long long answer; ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n; for (int i = 0; i < n; i++) { cin >> input; if (isPrime(input)) s.push(input); } if (s.empty()) cout << "-1"; else { answer = s.top(); s.pop(); while (!s.empty()) { answer = lcm(max(answer, s.top()), min(answer, s.top())); s.pop(); } cout << answer; } return (0); }