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 Solution { public List<String> generateParenthesis(int n) { List<String> list = new ArrayList<String>(); solve(n,0,0,"",list); return list; } private void solve(int n, int left, int right, String string, List<String> list) { if (left==n && right==n) { list.add(string); } if (left < n) { solve(n,left+1,right,string+‘(‘,list); } if (right<n && left>right) { solve(n,left,right+1,string+‘)‘,list); } } }
?
原文:http://hcx2013.iteye.com/blog/2216342