/*
 * @Author: Gtylcara.
 * @Date: 2021-03-27 00:07:00
 * @LastEditors: Gtylcara.
 * @LastEditTime: 2021-03-29 17:27:02
 */



var things = new Array();
var res = ""

function add()
{
    var t = document.getElementById('in').value
    if (t == "")
        return;


    for (var i in things)
    {
        if (t == things[i])
        {
            alert('元素重复');
            return;
        }
    }
    
    var id = things.length
    things.push(t);
    
    var box = document.getElementById('thingsBox')
    var btn = document.createElement('button')
    btn.id = 'btn' + t
    btn.onclick = function() {
        del(t)
    }
    btn.innerText = t
    box.appendChild(btn)

    // 
    // var text = document.getElementById('texts')
    // text.innerHTML = res;
    res = ""
}

function delall()
{
    console.log('clear')
    res = ""
    while (things.length > 0)
    {
        del(things[0]);
    }
    things.length = 0;
}

function del(id)
{
    
    console.log(id)

    var i = things.indexOf(id)
    console.log(i)
    var d = document.getElementById('btn' + id)
    d.remove();
    things.splice(i, 1)
    var text = document.getElementById('texts')
    text.innerHTML = "";
}

function start()
{
    full(things, 0, things.length)
    var text = document.getElementById('texts')
    text.innerHTML = res;
    res = ""
}


function swap(a, p, q) {
    var t = a[p];
    a[p] = a[q];
    a[q] = t;
}
function full(a, p, q) {
    if (p == q) {
        res += a;
        res += '。\n'
    }
    else {
        for (let i = p; i < q; i++) {
            swap(a, i, p);
            full(a, p + 1, q);
            swap(a, i, p);
        }
    }
}
// pai(a, 0, a.length);