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:
[
"((()))",
"(()())",
"(())()",
"()(())",
"()()()"
]
AC代码
void digui(vector<string>& ans, string str, int n, int numl, int numr) {
if (numl == n && numr == n) {
ans.push_back(str);
return;
}
if (numl < n) digui(ans, str + '(', n, numl + 1, numr);
if (numr < n && numr < numl) digui(ans, str + ')', n, numl, numr + 1);
}
class Solution {
public:
vector<string> generateParenthesis(int n) {
vector<string> ans;
string str;
digui(ans, str, n, 0, 0);
return ans;
}
};
总结
无
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