最长公共子括号序列

比较暴力的解法，没什么优化 import java.util.HashSet; public class TestKuoHao { private HashSet<String> set = new HashSet<>(); private boolean isLegal(char[] s) { if (s == null) return false; int count = 0; for (char c : s) { if (c == '(') { count++; } else { count--; } if (count < 0) return false; } return true; } private void swap(char[] a, int i, int j) { char temp = a[i]; a[i] = a[j]; a[j] = temp; } private int getCount(String s) { int len = s.length(); char[] a; set.add(s); for (int i = 0; i < len - 1; i++) { a = s.toCharArray(); for (int j = i; j < len - 1; j++) { swap(a, j, j + 1); if (isLegal(a)) { set.add(String.valueOf(a)); } } } for (int i = len - 1; i > 0; i--) { a = s.toCharArray(); for (int j = i; j > 0; j--) { swap(a, j, j - 1); if (isLegal(a)) { set.add(String.valueOf(a)); } } } set.remove(s); for(String ss : set) { System.out.println(ss); } return set.size(); } public static void main(String[] args) { String s = "(())()"; System.out.println(new TestKuoHao().getCount(s)); } }