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  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. /* Name of the class has to be "Main" only if the class is public. */
  8. class Ideone
  9. {
  10.  
  11. 	public static void main(final String[] args) {
  12. 		//Your input of [[1,0],[2,0],[3,3],[1,0,0],[2,0],[2,0,0],[0,0],[1,2] ] in a List of Lists
  13. 		final List<List<String>> input = createInput();
  14.  
  15. 		//To hold onto the groups for printing later
  16. 		final Map<Integer, List<List<String>>> groupsMap = new HashMap<Integer, List<List<String>>>();
  17.  
  18. 		//This will track the List<Integer> that have already been grouped.
  19. 		final List<List<String>> ungroupedLists = new ArrayList<List<String>>(input);
  20.  
  21. 		//Have a separate groupCounter so that we end up with continuous group numbers
  22. 		int groupCounter = 0;
  23.  
  24. 		for (int i = 0; i < input.size(); i++ ) {
  25. 			//This gets the group indexed at i (starting from 0 just like array
  26. 			final List<String> currentList = input.get(i);
  27.  
  28. 			//This checks if the currentList has already been grouped.
  29. 			//If it has, then continue to the next List.
  30. 			if( !ungroupedLists.contains(currentList) ) {
  31. 				continue;
  32. 			}
  33. 			//If it hasn't already been grouped, then remove it as we're going to group it now.
  34. 			ungroupedLists.remove(currentList);
  35.  
  36. 			//Create a new group to add any grouped lists to.
  37. 			final List<List<String>> currentGroup = new ArrayList<List<String>>();
  38. 			currentGroup.add(currentList);
  39.  
  40. 			//This list will hold the lists that get grouped so they can be removed for subsequent grouping runs.
  41. 			final List<List<String>> groupedLists = new ArrayList<List<String>>();
  42.  
  43. 			//For the ungrouped lists, check if they group with the current list.
  44. 			for (int j = 0; j < ungroupedLists.size(); j++) {
  45. 				//Get the list we want to compare the current one to.
  46. 				final List<String> currentComparisonList = ungroupedLists.get(j);
  47.  
  48. 				//Gets the first integer of the currentList
  49. 				final String integer = currentList.get(0);
  50. 				//Gets the last integer of the currentList
  51. 				final String integer2 = currentList.get(currentList.size()-1);
  52. 				//Gets the first integer of the currentComparisonList
  53. 				final String integer3 = currentComparisonList.get(0);
  54. 				//Gets the last integer of the currentComparisonList
  55. 				final String integer4 = currentComparisonList.get(currentComparisonList.size()-1);
  56.  
  57. 				//If the first Integers match, and the last integers match, add the currentComparisonList
  58. 				//to the group and makr it for removal later
  59. 				if( integer.equals(integer3) && integer2.equals(integer4) ) {
  60. 					currentGroup.add(currentComparisonList);
  61. 					groupedLists.add(currentComparisonList);
  62. 				}
  63. 			}
  64.  
  65. 			//Remove the now grouped lists.
  66. 			ungroupedLists.removeAll(groupedLists);
  67.  
  68. 			//When we've done all of that checking, add the group to the map of groups.
  69. 			groupsMap.put(groupCounter, currentGroup);
  70.  
  71. 			//Finally increment the groupCounter for the next group
  72. 			groupCounter++;
  73. 		}
  74.  
  75. 		//This simply prints the output in the format desired.
  76. 		for ( int i = 0; i < groupsMap.size(); i++ ) {
  77. 			System.out.println("group: " + i);
  78. 			for (final List<String> list : groupsMap.get(i)) {
  79. 				System.out.println(list.toString());
  80. 			}
  81. 		}
  82. 	}
  83.  
  84. 	private static List<List<String>> createInput() {
  85. 		final List<List<String>> input = new ArrayList<List<String>>();
  86. 		final ArrayList<String> list1 = new ArrayList<String>();
  87. 		list1.add("1");
  88. 		list1.add("0");
  89.  
  90. 		final ArrayList<String> list2 = new ArrayList<String>();
  91. 		list2.add("2");
  92. 		list2.add("0");
  93.  
  94. 		final ArrayList<String> list3 = new ArrayList<String>();
  95. 		list3.add("3");
  96. 		list3.add("3");
  97.  
  98. 		final ArrayList<String> list4 = new ArrayList<String>();
  99. 		list4.add("1");
  100. 		list4.add("0");
  101. 		list4.add("0");
  102.  
  103. 		final ArrayList<String> list5 = new ArrayList<String>();
  104. 		list5.add("2");
  105. 		list5.add("0");
  106.  
  107. 		final ArrayList<String> list6 = new ArrayList<String>();
  108. 		list6.add("2");
  109. 		list6.add("0");
  110. 		list6.add("0");
  111.  
  112. 		final ArrayList<String> list7 = new ArrayList<String>();
  113. 		list7.add("0");
  114. 		list7.add("0");
  115.  
  116. 		final ArrayList<String> list8 = new ArrayList<String>();
  117. 		list8.add("1");
  118. 		list8.add("2");
  119.  
  120. 		input.add(list1);
  121. 		input.add(list2);
  122. 		input.add(list3);
  123. 		input.add(list4);
  124. 		input.add(list5);
  125. 		input.add(list6);
  126. 		input.add(list7);
  127. 		input.add(list8);
  128. 		return input;
  129. 	}
  130. }
Success #stdin #stdout 0.07s 380224KB
comments (?)
stdin 
Standard input is empty
stdout 
group: 0
[1, 0]
[1, 0, 0]
group: 1
[2, 0]
[2, 0]
[2, 0, 0]
group: 2
[3, 3]
group: 3
[0, 0]
group: 4
[1, 2]
https://ideone.com/o4jJQ7
language:
Java (HotSpot 12)
created:
12 years ago
visibility:
public

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