[LeetCode] Generate Parentheses

题目：

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:

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

解答：

class Solution {public:    vector<string> result;    string s = "";    vector<string> generateParenthesis(int n) {        generate(n, n, s);        return result;    }        void generate(int left_leave, int right_leave, string s) {        if(left_leave == 0 && right_leave == 0) {            result.push_back(s);            return;        }                if(left_leave == right_leave) {            generate(left_leave - 1, right_leave, s + "(");        }                if(left_leave < right_leave) {            if(left_leave != 0) {                generate(left_leave - 1, right_leave, s + "(");            }            generate(left_leave, right_leave - 1, s + ")");        }            }};

思路：

递归，看代码应该很好理解，故不做赘述。