241126 디지털 티비

public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	int channelCount = Integer.parseInt(br.readLine());
	String[] channels = new String[channelCount + 1];
	int kbs1Position = 0;
	int kbs2Position = 0;
	StringBuilder buttonSequence = new StringBuilder();
	boolean isKbs1Found = false;

	for (int i = 1; i <= channelCount; i++) {
		String channelName = br.readLine();
		channels[i] = channelName;

		if (channelName.equals("KBS1")) {
			isKbs1Found = true;
			kbs1Position = i;
		}
		if (channelName.equals("KBS2")) {
			kbs2Position = i;
		}
		if (!isKbs1Found)
			buttonSequence.append("1");
	}

	channels[0] = "";
	String temp = channels[0];

	for (int i = 1; i <= kbs1Position; i++) {
		String currentChannel = channels[i];
		channels[i] = temp;
		temp = currentChannel;

		if (i != kbs1Position)
			buttonSequence.append("4");

		if (i != 2 && channels[i].equals("KBS2")) {
			kbs2Position = i;
		}
	}

	channels[1] = "KBS1";
	for (int i = 1; i < kbs2Position; i++) {
		buttonSequence.append("1");
	}
	for (int i = 2; i < kbs2Position; i++) {
		buttonSequence.append("4");
	}
	System.out.println(buttonSequence);
}

출처:https://www.acmicpc.net/problem/2816