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  1. import java.util.HashMap;
  2. import java.util.Map;
  3. import java.util.Stack;
  4.  
  5. /**
  6.  * Given an sequence of brackets , confirm if sequence is valid
  7.  * @author PRATEEK
  8.  */
  9. class ValidateBrackets {
  10.  
  11. 	private static Map<Character,Character> hash = new HashMap<>();
  12.  
  13. 	static {
  14. 		hash.put('{','}');
  15. 		hash.put('[',']');
  16. 		hash.put('(',')');
  17. 	}
  18.  
  19. 	/**
  20. 	 * Sub-routine to validate the sequence of brackets
  21. 	 * @param s
  22. 	 * @return
  23. 	 */
  24. 	public static boolean validate(String s){
  25. 		char[] arr = s.toCharArray();
  26.  
  27. 		Stack<Character> stack = new Stack<>();
  28. 		for(Character c:arr)
  29. 		{
  30. 			  switch (c) {
  31. 			case '[':
  32. 			case '{':
  33. 			case '(':
  34. 				stack.push(c);
  35. 				break;
  36.  
  37. 			case ']':
  38. 			case '}':
  39. 			case ')':
  40. 			{
  41. 				if(hash.values().contains(c))
  42. 				{
  43. 					if(!stack.isEmpty() && hash.get(stack.peek())==c)
  44. 						stack.pop();
  45. 					else if(stack.isEmpty())
  46. 						return false;
  47. 				}
  48.  
  49. 			}
  50. 				break;
  51. 			default:
  52. 				break;
  53. 			}
  54. 		}
  55. 		return stack.isEmpty();
  56. 	}
  57.  
  58. 	public static void main(String[] args) {
  59. 		String s= "{()}[]";
  60. 		boolean isValid = validate(s);
  61. 		System.out.println("input: "+s);
  62. 		System.out.println("output: " +isValid);
  63. 	}
  64. }
Success #stdin #stdout 0.07s 380224KB
comments (?)
stdin 
Standard input is empty
stdout 
input: {()}[]
output: true
https://ideone.com/1hqudG
Validate Brackets
language:
Java (HotSpot 12)
created:
10 years ago
visibility:
public

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