[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:

"((()))", "(()())", "(())()", "()(())", "()()()"

本题是括号匹配输出，利用迭代输出。时间：3ms

代码如下：

class Solution {
public:void unguarded_generate(vector<string> &result, string curr, int m, int n){if (m == 0 && n == 0){result.push_back(curr);}else{if (m != 0){cout << curr << endl;unguarded_generate(result, curr + "(", m - 1, n);}if (m < n && n != 0){cout << curr << endl;unguarded_generate(result, curr + ")", m, n - 1);}}}vector<string> generateParenthesis(int n) {vector<string> ret;if (n > 0){unguarded_generate(ret, string(), n, n);}return ret;}
};