[PS][그리디]/[BOJ][17451][평행 우주]

boj17451.cpp

#include <iostream>
using namespace std;

int n;
int spd[300000];
int main(void) { 
	cin >> n;
	int i = 0;
	for (i = 0; i < n; i++) {
		cin >> spd[i];
	}
	long long ans = 0;
	for (i = n - 1; i >= 0; i--) {
		if (ans < spd[i]) ans = 1LL * spd[i];
		else if (ans == spd[i]) continue;
		else {
			if (ans % spd[i] == 0) continue;
			ans = 1LL * ((ans / spd[i]) + 1) * spd[i];
		}
		//cout << ans << "\n";
	}
	cout << ans << "\n";
	return 0;
}