LeetCode-22.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:

[
  "((()))",
  "(()())",
  "(())()",
  "()(())",
  "()()()"
]

使用DFS+剪枝

class Solution {//DFS 剪枝 mytip
    public List<String> generateParenthesis(int n) {
        List<String> re = new ArrayList<>();
        generate(n,n,re,"");
        return re;
        
    }
    private void generate(int left,int right,List<String> re ,String s){
        if(0==left&&0==right){
            re.add(s);
            return;
        }
        if(left>0){
            generate(left-1,right,re,s+"(");
        }
        if(left<right){
            generate(left,right-1,re,s+")");
        }
    }
}

 

相关题

有效括号匹配 LeetCode20 https://www.cnblogs.com/zhacai/p/10429168.html