Brackets Sequence 括号DP

 1 import java.util.*;
 2 import java.io.*;
 3 import java.math.*;
 4 
 5 public class Main
 6 {
 7     static Scanner cin = new Scanner(new BufferedInputStream(System.in));
 8     public final static int MS= 105;
 9     static int[][] cnt = new int[MS][MS];
10     static String[][] ans = new String[MS][MS];
11     
12     
13     public static void main(String[] args)
14     {
15         String  str =  cin.nextLine();
16         str.replaceAll(" ","");
17         if(str.length() == 0)
18         {
19             System.out.println();
20             System.exit(0);
21         }
22         char[] ch = str.toCharArray();
23         int len = ch.length;
24         
25         for(int i = 0 ;i<len;i++)
26             for(int j = i;j< len;j++)
27                 cnt[i][j] = Integer.MAX_VALUE;
28         for(int i = 0;i<len;i++)
29             Arrays.fill(ans[i], "");
30         
31         for(int i = len -1;i>=0;i--)
32         {
33             for(int j = i;j<len;j++)
34             {
35                 if(i == j)
36                 {
37                     cnt[i][j] = 1;
38                     if(ch[i] == ‘(‘  || ch[i] == ‘)‘)
39                         ans[i][i] = "()";
40                     else
41                         ans[i][i] = "[]";
42                 }
43                 else
44                 {
45                     if(ch[i] == ‘(‘ && ch[j] == ‘)‘)
46                     {
47                         if(cnt[i+1][j-1] < cnt[i][j])
48                         {
49                             cnt[i][j] = cnt[i+1][j-1];
50                             ans[i][j] = "(" + ans[i+1][j-1] + ")";
51                             
52                         }
53                     }
54                     else if(ch[i] == ‘[‘ && ch[j] == ‘]‘)
55                     {
56                         if(cnt[i+1][j-1] < cnt[i][j])
57                         {
58                             cnt[i][j] = cnt[i+1][j-1];
59                             ans[i][j] = "[" + ans[i+1][j-1] + "]";
60                         }
61                     }
62                     //   求  cnt[i][j]的最小值。
63                     for(int k = i;k<j;k++)
64                     {
65                         if(cnt[i][k] + cnt[k+1][j] < cnt[i][j])
66                         {
67                             cnt[i][j] = cnt[i][k] + cnt[k+1][j];
68                             ans[i][j] = ans[i][k] + ans[k+1][j];
69                         }
70                     }
71                 }
72             }
73         }
74         System.out.println(ans[0][len-1]);
75     }
76 }