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  1. /* All Permutations of a String */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. /* Complexity O(n*n!) */
  8. class Ideone
  9. {
  10. 	public static ArrayList<String> strPerm(String str, ArrayList<String> list){
  11. 		int len = str.length();
  12. 		if(len==1){
  13. 			list.add(str);
  14. 			return list;
  15. 		}
  16.  
  17. 		list = strPerm(str.substring(0,len-1),list);
  18. 		int ls = list.size();
  19. 		char ap = str.charAt(len-1);
  20. 		for(int i=0;i<ls;i++){
  21. 			String temp = list.get(i);
  22. 			int tl = temp.length();
  23. 			for(int j=0;j<=tl;j++){
  24. 				list.add(temp.substring(0,j)+ap+temp.substring(j,tl));	
  25. 			}
  26. 		}
  27.  
  28. 		while(true){
  29. 			String temp = list.get(0);
  30. 			if(temp.length()<len)
  31. 				list.remove(temp);
  32. 			else
  33. 				break;
  34. 		}
  35.  
  36. 		return list;
  37. 	}
  38.  
  39. 	public static void main (String[] args) throws java.lang.Exception
  40. 	{
  41. 		String str = "abc";
  42. 		ArrayList<String> list = new ArrayList<>();
  43.  
  44. 		list = strPerm(str,list);
  45. 		System.out.println("Total Permutations : "+list.size());
  46. 		for(int i=0;i<list.size();i++)
  47. 			System.out.println(list.get(i));
  48.  
  49. 	}
  50. }
Success #stdin #stdout 0.08s 381248KB
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Standard input is empty
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Total Permutations : 6
cba
bca
bac
cab
acb
abc
https://ideone.com/nWPb3k
All Permutations of a String
language:
Java (HotSpot 12)
created:
10 years ago
visibility:
public

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