力扣，括号生成，js解法

源码：

var generateParenthesis = function(n) {
    const result = []
    dfs(n,n,'',result)
    return result
};

var dfs = function(left,right,str,result){
    if(left>right) return
    if(left===0&&right===0){
        result.push(str)
    } else{
        if(left>0) dfs(left-1,right,str+'(',result)
        if(right>0) dfs(left,right-1,str+')',result)
    }
}

结果：