The cycle, condition and probability of the JAVA Programmer's Interview (fourth edition)

Share content: about the use of collections

Page Number:77 pages

title: A String containing multiple characters in the a~z, if there are duplicates, such as string data = "AAVZCADFDSFSDHSHGWASDFASDFDDAAA", the most occurrences of the letter and the number of times, if there are multiple duplicates are found.

1 Importjava.util.ArrayList;2 Importjava.util.Collections;3 ImportJava.util.Iterator;4 ImportJava.util.TreeSet;5 6 7 8 9  Public classTest {Ten      One          Public Static  voidMain (string[] args) { AString input = "AAVZCADFDSFSDHSHGWASDFASDFDDAAA"; -             Newtest (). dostring (input); -     } the          -      Public voiddostring (String input) { -         Char[] chars =Input.tochararray (); -arraylist<string> lists =NewArraylist<string>(); +          -         //The first step is to pass the array to TreeSet, which automatically filters out the duplicate letters, and the collection is automatically sorted.  +Treeset<string> set =NewTreeset<string>(); A          for(inti=0;i<chars.length;i++){ at Lists.add (string.valueof (chars[i)); - Set.add (string.valueof (chars[i)); -         } -          -SYSTEM.OUT.PRINTLN (set);//output: [A, C, D, F, G, H, S, V, W, Z] -Collections.sort (lists);//Step Two: Use ArrayList for quick sorting inSYSTEM.OUT.PRINTLN (lists);//output: [A, a , A, a, a, a, a, a, C, D, D, D, D, D, D, D, F, F, F, F, G, H, H, S, S, S, S, S, V, W, Z] -          toStringBuffer SB =NewStringBuffer (); +          for(intI=0;i<lists.size (); i++){ - Sb.append (Lists.get (i)); the         } *          $input =sb.tostring ();Panax NotoginsengSYSTEM.OUT.PRINTLN (input);//Output: Aaaaaaaacdddddddffffghhsssssvwz -         intMax = 0; theString maxstring = ""; +Arraylist<string> maxlist =NewArraylist<string>(); A          theIterator its =set.iterator (); +          while(Its.hasnext ()) { -String OS =(String) Its.next (); $             intBegin =input.indexof (OS); $             intend = Input.lastindexof (OS);//Step three: Use IndexOf and lastIndexOf to find the maximum value.  -             intValue = End-begin +1; -             if(value>max) { theMax =value; -Maxstring =os;Wuyi maxlist.add (OS); the}Else if(value==max) { - maxlist.add (OS); Wu             } -         } About          $System.out.println ("maxstring:" +maxstring);//Output: Maxstring:a -System.out.println ("maxlist:" +maxlist);//output: Maxlist:[a] -          -         intindex = 0; A          for(intI=0;i<maxlist.size (); i++){ +             if(Maxlist.get (i). Equals (maxstring)) { theindex =i; -                  Break; $             } the         } the          theSystem.out.print ("Max data:");//output: Max data:a the          for(intI=index;i<maxlist.size (); i++){ -System.out.println (Maxlist.get (i) + ""); in         } the          the System.out.println (); AboutSystem.out.println ("Max:" +max);//Output: Max:8 the          the         }     the      +      -}

The reason for sharing This example is that it contains some examples of collections (TreeSet, ArrayList, IndexOf, lastIndexOf), and it feels more classic to share, and of course this article I would like to share some examples of recursion, But I feel that the understanding of recursion is relatively superficial, and so I take a time to study, then come out to share.

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The cycle, condition and probability of the JAVA Programmer's Interview (fourth edition)