LeetCode - 22. Generate Parentheses

 22. Generate Parentheses#

Problem's Link
#

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Mean: 

给定一个数n，输出由2*n个'('和')'组成的字符串，该字符串符合括号匹配规则.

analyse:

递归求解.

Time complexity: O(N)

 

view code

/**
* -----------------------------------------------------------------
* Copyright (c) 2016 crazyacking.All rights reserved.
* -----------------------------------------------------------------
*       Author: crazyacking
*       Date  : 2016-02-17-17.58
*/
#include <queue>
#include <cstdio>
#include <set>
#include <string>
#include <stack>
#include <cmath>
#include <climits>
#include <map>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long(LL);
typedef unsigned long long(ULL);
const double eps(1e-8);

class Solution
{
public:
   vector<string> generateParenthesis(int n)
   {
       vector<string> res;
       recursive(res,"",n,0);
       return res;
   }
   void recursive(vector<string>& v,string str,int n,int m)
   {
       if(n==0 && m==0)
       {
           v.push_back(str);
           return;
       }
       if(m>0)
           recursive(v,str+")",n,m-1);
       if(n>0)
           recursive(v,str+"(",n-1,m+1);
   }
};

int main()
{
   Solution solution;
   int n;
   while(cin>>n)
   {
       auto ans=solution.generateParenthesis(n);
       for(auto p:ans)
       {
           cout<<p<<endl;
       }
       cout<<"End."<<endl;
   }
   return 0;
}
/*

*/