题目:
给出 n 代表生成括号的对数,请你写出一个函数,使其能够生成所有可能的并且有效的括号组合。
示例 1:
例如,给出 n = 3,生成结果为:
[
"((()))",
"(()())",
"(())()",
"()(())",
"()()()"
]
代码1:
class Solution {
public List<String> generateParenthesis(int n) {
List<String> list = new ArrayList<>();
helper(list,"",0,0,n);
return list;
}
private void helper(List<String> list,String temp,int open,int close,int n){
if(open == n && close == n){
list.add(temp);
return;
}
if(open < n){
helper(list,temp+"(",open+1,close,n);
}
if(close < open){
helper(list,temp+")",open,close+1,n);
}
}
}