var countAndSay = function(n) {
if(n==1) return '1';
let pre = countAndSay(n-1);//递归
let result = '';
let count = 1;
for(let i=0;i<pre.length;i++){
if(pre[i] == pre[i+1]){
count++; //计算有多少个该数
}else{
result += count+pre[i];
count = 1; //已经将值加给result了,可以恢复为1,继续下一次
}
}
return result;
};