[LeetCode 22]Generate Parentheses

题目链接：generate-parentheses

import java.util.ArrayList;import java.util.List;/** * 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:"((()))", "(()())", "(())()", "()(())", "()()()" * */public class GenerateParentheses {//8 / 8 test cases passed.//Status: Accepted//Runtime: 213 ms//Submitted: 0 minutes ago//时间复杂度O(2^n) 空间复杂度 O(1)public List<String> parenthesis = new ArrayList<String>();public List<String> generateParenthesis(int n) {generateParenthesis(n, n, "");return parenthesis;}// left 表示剩余"("数量， right表示剩余")"数量public void generateParenthesis(int left, int right, String s) {if(left == 0) {while(right != 0) {s += ")";right –;}parenthesis.add(s);return;}//选中"("generateParenthesis(left – 1, right, s + "(");//当剩余 ")" 数大于 "(" 数时，选中 ")"if(right > left) {generateParenthesis(left, right – 1, s + ")");}}public static void main(String[] args) {//System.out.println(Arrays.toString(generateParenthesis(0).toArray()));}}

，微笑的去寻找一个不可能出现的你。