let a="asd".split('');
let all=[];
function p(arr){
if(arr.length===1)return arr;
for(let i=0;i<arr.length;i++){
return(arr[i],p(arr.slice(1)));
}
return p(arr);
}
p(a);
console.log(p(a));
bGV0IGE9ImFzZCIuc3BsaXQoJycpOwpsZXQgYWxsPVtdOwpmdW5jdGlvbiBwKGFycil7CglpZihhcnIubGVuZ3RoPT09MSlyZXR1cm4gYXJyOwoJZm9yKGxldCBpPTA7aTxhcnIubGVuZ3RoO2krKyl7CgkJcmV0dXJuKGFycltpXSxwKGFyci5zbGljZSgxKSkpOwoJCQoJfQoJcmV0dXJuIHAoYXJyKTsKfQpwKGEpOwpjb25zb2xlLmxvZyhwKGEpKTs=