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