|
| 1 | +``` |
| 2 | +import java.io.*; |
| 3 | +import java.util.*; |
| 4 | +
|
| 5 | +public class Main { |
| 6 | + private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); |
| 7 | + private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); |
| 8 | + private static List<int[]> reverse; |
| 9 | + private static int N, M; |
| 10 | + public static void main(String[] args) throws IOException { |
| 11 | + init(); |
| 12 | + if (reverse.isEmpty()) { |
| 13 | + bw.write(M + "\n"); |
| 14 | + } else { |
| 15 | + reverse.sort((o1, o2) -> { |
| 16 | + if (o1[0] == o2[0]) return Integer.compare(o1[1], o2[1]); |
| 17 | + return Integer.compare(o1[0], o2[0]); |
| 18 | + }); |
| 19 | +
|
| 20 | + List<int[]> list = new ArrayList<>(); |
| 21 | + int[] current = reverse.get(0); |
| 22 | +
|
| 23 | + for (int i = 1; i < reverse.size(); i++) { |
| 24 | + int[] next = reverse.get(i); |
| 25 | + if (current[1] >= next[0]) { |
| 26 | + current[1] = Math.max(current[1], next[1]); |
| 27 | + } else { |
| 28 | + list.add(new int[]{current[0], current[1]}); |
| 29 | + current = next; |
| 30 | + } |
| 31 | + } |
| 32 | +
|
| 33 | + list.add(current); |
| 34 | +
|
| 35 | + long temp = M; |
| 36 | +
|
| 37 | + for (int[] element : list) { |
| 38 | + temp += (element[1] - element[0]) * 2L; |
| 39 | + } |
| 40 | +
|
| 41 | + bw.write(temp + "\n"); |
| 42 | + } |
| 43 | + bw.flush(); |
| 44 | + bw.close(); |
| 45 | + br.close(); |
| 46 | + } |
| 47 | +
|
| 48 | + private static void init() throws IOException { |
| 49 | + StringTokenizer st = new StringTokenizer(br.readLine()); |
| 50 | + N = Integer.parseInt(st.nextToken()); |
| 51 | + M = Integer.parseInt(st.nextToken()); |
| 52 | +
|
| 53 | + reverse = new ArrayList<>(); |
| 54 | +
|
| 55 | + for (int i = 0; i < N; i++) { |
| 56 | + st = new StringTokenizer(br.readLine()); |
| 57 | + int x = Integer.parseInt(st.nextToken()); |
| 58 | + int y = Integer.parseInt(st.nextToken()); |
| 59 | +
|
| 60 | + if (x > y) { |
| 61 | + reverse.add(new int[]{y, x}); |
| 62 | + } |
| 63 | + } |
| 64 | + } |
| 65 | +} |
| 66 | +
|
| 67 | +``` |
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