<script type="text/javascript">

//氣泡排序
function bubbleSort(arr){
    var i = j = 0;
    for(i=1;i<arr.length;i++){
        for(j=0;j<=arr.length-i;j++){
            var temp = 0;
            if(arr[j]>arr[j+1]){
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
    }
    return arr;
}

console.log(bubbleSort([{a:3},{a:2}]))


// 快速排序
function quickSort(arr){
    //如果陣列<=1,則直接返回
    if(arr.length<=1){return arr;}
    var pivotIndex=Math.floor(arr.length/2);
    //找基準，並把基準從原陣列刪除
    var pivot=arr.splice(pivotIndex,1)[0];
    //定義左右陣列
    var left=[];
    var right=[];

    //比基準小的放在left，比基準大的放在right
    for(var i=0;i<arr.length;i++){
        if(arr[i]<=pivot){
            left.push(arr[i]);
        }
        else{
            right.push(arr[i]);
        }
    }
    //遞迴
    return quickSort(left).concat([pivot],quickSort(right));
}    

console.log(quickSort([1,2,3,0]))


// 歸併排序
function mergeSort(items) {
    if (items.length < 2) {
        return items;
    }
    var middle = Math.floor(items.length / 2),
        left = items.slice(0, middle),
        right = items.slice(middle),
        params = merge(mergeSort(left), mergeSort(right));

    params.unshift(0, items.length);
    // 原來的items替換成排序後的params
    items.splice.apply(items, params);

    return items;

    function merge(left, right) {
        var result = [],
            il = 0,
            ir = 0;

        while (il < left.length && ir < right.length) {
            if (left[il] < right[ir]) {
                result.push(left[il++]);
            } else {
                result.push(right[ir++]);
            }
        }

        return result.concat(left.slice(il)) .concat(right.slice(ir));
    }
}

var arr = [2, 1, 3, 12, 5, 66, 23, 87, 15, 32];

console.log(mergeSort(arr));

</script>