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  1. import java.io.BufferedReader;
  2. import java.io.IOException;
  3. import java.io.InputStreamReader;
  4. import java.util.ArrayDeque;
  5. import java.util.ArrayList;
  6. import java.util.Deque;
  7.  
  8. public class Main {
  9. 	private final RoomNode[] rooms;
  10. 	private final int passages;
  11.  
  12. 	private long noOfPairsWhichHaveDraughts = 0;
  13. 	private long noOfRoomsWithAtleastOneDraught = 0;
  14.  
  15. 	public Main(BufferedReader in) throws Exception {
  16.  
  17. 		String[] roomAndPassage = in.readLine().split(" ");
  18. 		int noOfRooms = Integer.parseInt(roomAndPassage[0]);
  19. 		if (noOfRooms > 50000) {noOfRooms = 50000;}
  20. 		passages = Integer.parseInt(roomAndPassage[1]);
  21.  
  22. 		rooms = new RoomNode[noOfRooms];
  23.  
  24. 		setRoomsWithOpenWindows(in);
  25. 		setPairsWithDraughts(in);
  26. 		findSolution();
  27. 	}	
  28.  
  29.  
  30. 	private void setRoomsWithOpenWindows(BufferedReader in) throws IOException, Exception {	
  31.  
  32. 		int i = 0;
  33. 		String[] line = in.readLine().trim().split(" ");
  34.  
  35. 		for (String roomToken : line) {
  36. 			boolean openWindow = Integer.parseInt(roomToken) == 1? true:false;
  37. 			rooms[i] = new RoomNode(openWindow);
  38. 			i++;
  39. 			if (i>=rooms.length) {break;}
  40. 		}
  41. 	}
  42.  
  43.  
  44. 	private void setPairsWithDraughts(BufferedReader in) throws NumberFormatException, IOException, Exception {
  45.  
  46. 		String line = null;
  47. 		int i = 0;
  48. 		while((line = in.readLine()) != null && !line.isEmpty() & i <= passages) {
  49. 			line = line.trim();
  50. 			String[] lineTokens = line.split(" ");
  51. 			RoomNode room1 = rooms[Integer.parseInt(lineTokens[0])-1];
  52. 			RoomNode room2 = rooms[Integer.parseInt(lineTokens[1])-1];
  53. 			room1.addLinks(room2);
  54. 			room2.setParent(room1);
  55. 			i++;
  56. 		}
  57. 	}
  58.  
  59.  
  60. 	private void findSolution() {
  61.  
  62. 		Deque<RoomNode> stack = new ArrayDeque<>();
  63. 		int pruned = 0;
  64. 		int openCount = 0;
  65.  
  66. 		for (RoomNode room: rooms) {
  67. 			pruned += pruneTree(room);
  68. 			if (room.isVisited() || !room.isOpenWindow()) {continue;}
  69. 			stack.clear();
  70. 			stack.push(room);
  71.  
  72. 			while(!stack.isEmpty()) {
  73. 				RoomNode node = stack.pop();
  74. 				node.setVisited(true);
  75. 				if (node.isOpenWindow()) {openCount++;}
  76. 				stack.addAll(node.getLinks());
  77. 			}
  78. 		}
  79. 		if (openCount > 1) {
  80. 			noOfPairsWhichHaveDraughts += ((openCount * (openCount-1))/2);
  81. 			noOfRoomsWithAtleastOneDraught = rooms.length - pruned;
  82. 		}
  83. 	}
  84.  
  85.  
  86. 	private int pruneTree(RoomNode room) {
  87.  
  88. 		Deque<RoomNode> stack = new ArrayDeque<>();
  89. 		int pruned = 0;
  90.  
  91. 		if (room.isOpenWindow()) {return 0;}
  92. 		stack.push(room);
  93. 		while(!stack.isEmpty()) {
  94. 			RoomNode node = stack.pop();
  95. 			if (!node.isOpenWindow() && node.getLinks().isEmpty()) {
  96. 				pruned++;
  97. 				node.parent.getLinks().remove(node);
  98. 				stack.push(node.getParent());
  99. 			}
  100. 		}
  101. 		return pruned;
  102. 	}
  103.  
  104.  
  105. 	public String getSolution() {
  106. 		return noOfPairsWhichHaveDraughts + " " + noOfRoomsWithAtleastOneDraught;
  107. 	}
  108.  
  109.  
  110. 	public static void main(String[] args) {
  111. 		Main draughts;
  112. 		try (BufferedReader in = new BufferedReader(new InputStreamReader(System.in))){
  113. 			draughts = new Main(in);
  114. 			System.out.println(draughts.getSolution());
  115. 		} catch (Exception e) {
  116. 			e.printStackTrace();
  117. 		}
  118. 		System.exit(0);
  119. 	}
  120.  
  121.  
  122. 	private class RoomNode {
  123.  
  124. 		private final boolean openWindow;
  125. 		private final ArrayList<RoomNode> links = new ArrayList<>();
  126. 		private RoomNode parent;
  127. 		private boolean visited;
  128.  
  129. 		public RoomNode (boolean openWindow) {
  130.  
  131. 			this.openWindow = openWindow;
  132. 			visited = false;
  133. 			setParent(null);
  134. 		}
  135.  
  136. 		public boolean isOpenWindow() {
  137. 			return openWindow;
  138. 		}
  139.  
  140. 		public void addLinks(RoomNode link) {
  141. 			links.add(link);
  142. 		}
  143.  
  144. 		public ArrayList<RoomNode> getLinks() {
  145. 			return links;
  146. 		}
  147.  
  148. 		public boolean isVisited() {
  149. 			return visited;
  150. 		}
  151.  
  152. 		public void setVisited(boolean visited) {
  153. 			this.visited = visited;
  154. 		}
  155.  
  156. 		public RoomNode getParent() {
  157. 			return parent;
  158. 		}
  159.  
  160. 		public void setParent(RoomNode parent) {
  161. 			this.parent = parent;
  162. 		}	
  163. 	}
  164. }
Success #stdin #stdout #stderr 0.08s 380160KB
comments (?)
stdin
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6 3
1 0 1 0 1 0
1 2
3 4
4 1
stdout
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Standard output is empty
stderr
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java.lang.NullPointerException
	at Main.pruneTree(Main.java:97)
	at Main.findSolution(Main.java:67)
	at Main.<init>(Main.java:26)
	at Main.main(Main.java:113)
	Suppressed: java.io.IOException: Permission denied
		at java.io.FileInputStream.close0(Native Method)
		at java.io.FileInputStream.close(FileInputStream.java:326)
		at java.io.BufferedInputStream.close(BufferedInputStream.java:472)
		at sun.nio.cs.StreamDecoder.implClose(StreamDecoder.java:377)
		at sun.nio.cs.StreamDecoder.close(StreamDecoder.java:192)
		at java.io.InputStreamReader.close(InputStreamReader.java:199)
		at java.io.BufferedReader.close(BufferedReader.java:517)
		at Main.main(Main.java:115)
https://ideone.com/mBACo4
language:
Java (HotSpot 12)
created:
10 years ago
visibility:
public

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