# 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:
[
"((()))",
"(()())",
"(())()",
"()(())",
"()()()"
]
# Solution
Approach 1: Backtracking.
# Code (Python)
Approach 1:
# Code (C++)
Approach 1:
class Solution {
private:
void generateParenthesis(vector<string>& strSet, string str, int open, int close) {
if (open == 0 && close == 0)
{
strSet.push_back(str);
return;
}
if (open > 0)
generateParenthesis(strSet, str + "(", open - 1, close);
if (open < close)
generateParenthesis(strSet, str + ")", open, close - 1);
}
public:
vector<string> generateParenthesis(int n) {
vector<string> strSet;
generateParenthesis(strSet, "", n, n);
return strSet;
}
};