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  1. import java.util.*;
  2. import java.lang.*;
  3. import java.io.*;
  4.  
  5.  class Ideone {
  6. 	public static void main (String[] args) {
  7.  
  8. 		//create an DB for online and reged users
  9. 		Map DB = new HashMap<String, String> (); 
  10. 		HashSet <String> DBin = new HashSet <String> ();
  11.  
  12. 		Scanner in = new Scanner (System.in);
  13. 		PrintWriter out = new PrintWriter(System.out);
  14.  
  15. 		//a number of queries
  16. 		int n = in.nextInt();
  17.  
  18.  
  19. 		for (int i = 0; i < n; i++){
  20. 			String s, log, pass;
  21.  
  22. 			//command
  23. 			s = in.next();
  24.  
  25. 			if (s.equals("register")){
  26. 			    log = in.next(); 	//login
  27. 			    pass = in.next();	//password
  28. 				if (DB.containsKey(log)){	//login in DB?
  29. 					out.println("fail: user already exists");
  30. 					out.flush();
  31. 				}
  32. 				else {
  33. 					DB.put(log, pass);
  34. 					out.println("success: new user added");
  35. 					out.flush();
  36. 				}
  37. 			}
  38.  
  39. 			if (s.equals("login")){
  40. 			    log = in.next();
  41. 			    pass = in.next();
  42. 				if (DB.containsKey(log)){ //if user is reg
  43. 					if (pass.equals(DB.get(log))) {	//if the password is well
  44. 						if (!DBin.contains(log)) {	//online?
  45. 							DBin.add(log);
  46. 							out.println("success: user logged in");
  47. 							out.flush();
  48. 						}
  49. 						//Errors
  50. 						else {
  51. 							out.println("fail: already logged in");
  52. 							out.flush();
  53. 						}
  54. 					}
  55. 					else {
  56. 						out.println("fail: incorrect password");
  57. 						out.flush();
  58. 					}
  59. 				}
  60. 				else {
  61. 					out.println("fail: no such user");
  62. 					out.flush();
  63. 				}
  64. 			}
  65. 			if (s.equals("logout")){
  66. 			    log = in.next();
  67. 				if (!DB.containsKey(log)) { //unreg user can't logout... unfortunately.
  68. 					out.println("fail: no such user");
  69. 					out.flush();
  70. 				}
  71. 				else {
  72. 					if (!DBin.contains(log)){	//so offline user does
  73. 						out.println("fail: already logged out");
  74. 						out.flush();
  75. 					}
  76. 					else {
  77. 						DBin.remove(log);
  78. 						out.println("success: user logged out");
  79. 						out.flush();
  80. 					}
  81. 				}
  82. 			}
  83. 		}
  84. 	}
  85. }
Success #stdin #stdout 0.14s 321344KB
comments (?)
stdin 
6
register vasya 12345
login vasya 1234
login vasya 12345
login anakin C-3PO
logout vasya
logout vasya
stdout 
success: new user added
fail: incorrect password
success: user logged in
fail: no such user
success: user logged out
fail: already logged out
https://ideone.com/EDX3xm
language:
Java (12.0.1)
created:
9 years ago
visibility:
secret

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