A5:有效括号序列

 1 import java.util.LinkedList;
 2 
 3 /**
 4  * Created by Tutotu on 2017/2/11.
 5  * <p>
 6  * Realname:yangmingzhu
 7  * <p>
 8  * Tel:18511400217
 9  * <p>
10  * Email:yangmingzhu921025@hotmail.com
11  */
12 
13 public class Solution8 {
14 
15     LinkedList<Character> stack = new LinkedList<Character>();
16 
17     public boolean isValidParentheses(String s) {
18         // Write your code here
19         boolean result = false;
20         if(s.length() == 0){
21             return false;
22         }else {
23             char[] c = s.toCharArray();
24             for(int i=0; i<s.length(); i++){
25 
26                 if(stack.isEmpty()){
27                     push(stack,c[i]);
28                 }else{
29                     if(stack.getLast() == reverse(c[i])){
30                         char tmp = pop(stack);
31                         if(tmp == ‘)‘ || tmp == ‘}‘ || tmp == ‘]‘){
32                             result = false;
33                             break;
34                         }
35                     }else{
36                         push(stack,c[i]);
37                     }
38                 }
39                 System.out.println(stack);
40             }
41             if(isEmpty(stack)) result = true;
42         }
43 
44         return result;
45     }
46 
47     private char pop(LinkedList<Character> stack){
48         return stack.removeLast();
49     }
50 
51     private void push(LinkedList<Character> stack, char s){
52         stack.addLast(s);
53     }
54 
55     private boolean isEmpty(LinkedList<Character> stack){
56         if (stack.isEmpty()){
57             return true;
58         }else
59             return false;
60 
61     }
62 
63     private char reverse(char c){
64         char res = ‘ ‘;
65         if (c == ‘(‘) res =  ‘)‘;
66         else if(c == ‘)‘) res = ‘(‘;
67         else if(c == ‘[‘) res = ‘]‘;
68         else if(c == ‘]‘) res = ‘[‘;
69         else if(c == ‘{‘) res = ‘}‘;
70         else if(c == ‘}‘) res = ‘{‘;
71         return res;
72     }
73 
74     public static void main(String[] args){
75         Solution8 s = new Solution8();
76         System.out.println(s.isValidParentheses("([])"));
77     }
78 }