C++ 解法, 执行用时: 0ms, 内存消耗: 8552KB, 提交时间: 2015-03-26

class Solution {
public:
    void dfs(int x,int y,int tot,int n,char *s,vector<string>&res){
        if(x==n&&y==n){
            s[tot]='\0';
            //cout<<s<<endl;
            string ss=s;
            res.push_back(ss);
            return ;
        }
        if(x<n){
            s[tot]='(';
            dfs(x+1,y,tot+1,n,s,res);
        }
        if(x>y){
            s[tot]=')';
            dfs(x,y+1,tot+1,n,s,res);
        }
    }
    vector<string> generateParenthesis(int n) {
        char s[100];
        vector<string>res;
        dfs(0,0,0,n,s,res);
        return res;
    }
};

C++ 解法, 执行用时: 0ms, 内存消耗: 8552KB, 提交时间: 2015-03-26

vector<string> res;
int cnt;
void build(vector<char> s, int l,int v){
	if (s.size() == cnt * 2){
		string t = "";
		for (int i = 0; i < s.size(); i++)
			t += s[i];
		res.push_back(t);
		return;
	}
	if (l < cnt){
		vector<char> a = s;
		a.push_back('(');
		build(a, l + 1, v + 1);
	}
	if (v > 0){
		vector<char> a = s;
		a.push_back(')');
		build(a, l, v - 1);
	}
}

class Solution {
public:
	vector<string> generateParenthesis(int n) {
		res.clear();
		cnt = n;
		vector<char> e;
		build(e, 0, 0);
		return res;
	}
	
};

C 解法, 执行用时: 3ms, 内存消耗: 392KB, 提交时间: 2022-06-02

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param n int整型 
 * @return string字符串一维数组
 * @return int* returnSize 返回数组行数
 *
 * C语言声明定义全局变量请加上static，防止重复定义
 */
static int hang = 0;
void dfs(char** resu, int n, int left, int right, char str[])
{
    if(left == n && right == n)
    {
        char* tmp = (char*)malloc(sizeof(char)*n*2);
        memcpy(tmp, str, n*2);
        resu[hang++] = tmp;

        return ;
    }
    
    if(left < n)
    {
        str[left+right] = '(';
        dfs(resu, n, left+1, right, str);
    }

    if(right < n && right < left)
    {
        str[left+right] = ')';
        dfs(resu, n, left, right+1, str);
    }
    
    return ;
}

char** generateParenthesis(int n, int* returnSize) {
    // write code here
    if(n == 0) return NULL;
    
    char** resu = (char**)malloc(sizeof(char*)*100000);

    
    int left = 0;
    int right = 0;
    char str[21] = {'\0'};
    dfs(resu, n, left, right, str);
    * returnSize = hang;
    return resu;
}

Rust 解法, 执行用时: 3ms, 内存消耗: 396KB, 提交时间: 2022-06-26

struct Solution{

}

impl Solution {
    fn new() -> Self {
        Solution{}
    }

    /**
    * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
    *
    * 
        * @param n int整型 
        * @return string字符串一维数组
    */
    pub fn generateParenthesis(&self, n: i32) -> Vec<String> {
        // write code here
        let mut store = vec![];
        let mut s = String::new();
        let mut n = n as usize;
        produce(&mut store, n, n, &mut s);
        return store;
    }
}

fn produce(store: &mut Vec<String>, l: usize, r: usize, s: &mut String) {
    if l == 0 && r == 0 {
        store.push(s.clone());
        return;
    }
    
    if l == 0 && r > 0 {
        s.push(')');
        produce(store, l, r - 1, s);
        s.pop();
        return;
    }
    
    if r == 0 && l > 0 {
        s.push('(');
        produce(store, l - 1, r, s);
        s.pop();
        return;
    }
    
    if l < r {
        s.push('(');
        produce(store, l - 1, r, s);
        s.pop();
        s.push(')');
        produce(store, l, r - 1, s);
        s.pop();
        return;
    }
    
    if l >= r {
        s.push('(');
        produce(store, l - 1, r, s);
        s.pop();
    }
}

C++ 解法, 执行用时: 3ms, 内存消耗: 412KB, 提交时间: 2022-07-27

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param n int整型 
     * @return string字符串vector
     */
    void recursion(int left, int right, vector<string>& res, string temp, int n)
    {
        if(left == n && right == n)
        {
            res.push_back(temp);
            return;
        }
        
        if(left < n)
        {
            recursion(left + 1, right, res, temp + "(", n);
        }
        
        if(right < n && left > right)
            recursion(left, right + 1, res, temp + ")", n);
        
    }
    
    vector<string> generateParenthesis(int n) {
        vector<string> res;
        string temp = "";
        recursion(0, 0, res, temp, n);
        
        return res;
        
    }
};