题解 | #括号生成#

/**
  * 
  * @param n int整型 
  * @return string字符串一维数组
  */
function generateParenthesis( n ) {
    // write code here
    let result = []
  //let temp = n.split('');
  dfs(n, n, '', result);  // 一开始左右括号的数量都为n
  return result;
   function dfs (left,right,str,result){
    if(left > right)return
    if(left === 0 && right === 0 ){
      result.push(str)
    }
    if(left > 0){
      dfs(left-1,right,str+'(',result)
    }
    if(right > 0){
      dfs(left,right-1,str+')',result)
    }
  }
}
module.exports = {
    generateParenthesis : generateParenthesis
};