Given n pairs of parentheses, write a function to generate all combinations of wellformed parentheses.
For example, given n = 3, a solution set is:
"((()))", "(()())", "(())()", "()(())", "()()()"
该题目有一个规则是左括号个数得小于右括号个数，根据这个规则，可用通过动态规划来解决这个题目
package com.lilei.myes.es.pack1107;
public class generate_parentheses {
public static void main(String[] args) {
int num = 4;
genp("", num, num);
}
public static void genp(String s, int left, int right) {
if (left > 0 && right > 0) {
if (left == right) {
genp(s + "(", left - 1, right);
} else if (left < right) {
genp(s + "(", left - 1, right);
genp(s + ")", left, right - 1);
}
} else {
for (int i = 0; i < right; i++)
s = s + ")";
System.out.println(s);
}
}
}
原文：http://www.cnblogs.com/lilei2blog/p/7799586.html