240502 주유소

public static void main(String[] args) throws Exception {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
	
	int n = Integer.parseInt(br.readLine()) - 1;
	StringTokenizer st1 = new StringTokenizer(br.readLine());
	StringTokenizer st2 = new StringTokenizer(br.readLine());

	long min = Integer.MAX_VALUE;
	long result = 0;

	for (int i = 0; i < n; i++) {
		min = Math.min(min, Integer.parseInt(st2.nextToken()));
		result += min * Integer.parseInt(st1.nextToken());
	}

	bw.write(Long.toString(result));
	bw.flush();
	bw.close();
}

출처:https://www.acmicpc.net/problem/13305