Leetcode之generate Parentheses

26 June 2014

Generate Parentheses

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

For example, given n = 3, a solution set is:
"((()))", "(()())", "(())()", "()(())", "()()()" 

解法：穷举组合问题，使用递归。(())(())这种情况很容易漏掉。

代码如下：

//{java}
public class Solution {
    public List<String> generateParenthesis(int n) {
        List<String> ls = new ArrayList<String>();
        if(n==0)
        {
            ls.add("");
            return ls;
        }
        Set<String> set = new HashSet<String>();
        for(String temp:generateParenthesis(n-1))
        {
            set.add("()"+temp);
            set.add(temp+"()");
            for(int i=0;i<temp.length();i++)
            {
                if(temp.charAt(i)=='(')
                {
                    set.add(temp.substring(0,i+1)+"()"+temp.substring(i+1,temp.length()));
                }
            }
        }
        ls.addAll(set);
        return ls;
    }
}

LeetCode 47

LeetCode，面试，组合穷举，括号组合，递归 1

Leetcode之generate Parentheses 括号所有组合

Generate Parentheses