JavaScript常用算法比较

JAVASCRIPT算法比较

<script>
    Array.prototype.swap = function(i, j)
    {
        var temp = this[i];
        this[i] = this[j];
        this[j] = temp;
    }

    Array.prototype.bubbleSort = function()
    {
        for (var i = this.length - 1; i > 0; --i)
        {
            for (var j = 0; j < i; ++j)
            {
                if (this[j] > this[j + 1]) this.swap(j, j + 1);
            }
        }
    }

    Array.prototype.selectionSort = function()
    {
        for (var i = 0; i < this.length; ++i)
        {
            var index = i;
            for (var j = i + 1; j < this.length; ++j)
            {
                if (this[j] < this[index]) index = j;
            }
            this.swap(i, index);
        }
    }

    Array.prototype.insertionSort = function()
    {
        for (var i = 1; i < this.length; ++i)
        {
            var j = i, value = this[i];
            while (j > 0 && this[j - 1] > value)
            {
                this[j] = this[j - 1];
                --j;
            }
            this[j] = value;
        }
    }

    Array.prototype.shellSort = function()
    {
        for (var step = this.length >> 1; step > 0; step >>= 1)
        {
            for (var i = 0; i < step; ++i)
            {
                for (var j = i + step; j < this.length; j += step)
                {
                    var k = j, value = this[j];
                    while (k >= step && this[k - step] > value)
                    {
                        this[k] = this[k - step];
                        k -= step;
                    }
                    this[k] = value;
                }
            }
        }
    }

    Array.prototype.quickSort = function(s, e)
    {
        if (s == null) s = 0;
        if (e == null) e = this.length - 1;
        if (s >= e) return;
        this.swap((s + e) >> 1, e);
        var index = s - 1;
        for (var i = s; i <= e; ++i)
        {
            if (this[i] <= this[e]) this.swap(i, ++index);
        }
        this.quickSort(s, index - 1);
        this.quickSort(index + 1, e);
    }

    Array.prototype.stackQuickSort = function()
    {
        var stack = [0, this.length - 1];
        while (stack.length > 0)
        {
            var e = stack.pop(), s = stack.pop();
            if (s >= e) continue;
            this.swap((s + e) >> 1, e);
            var index = s - 1;
            for (var i = s; i <= e; ++i)
            {
                if (this[i] <= this[e]) this.swap(i, ++index);
            }
            stack.push(s, index - 1, index + 1, e);
        }
    }

    Array.prototype.mergeSort = function(s, e, b)
    {
        if (s == null) s = 0;
        if (e == null) e = this.length - 1;
        if (b == null) b = new Array(this.length);
        if (s >= e) return;
        var m = (s + e) >> 1;
        this.mergeSort(s, m, b);
        this.mergeSort(m + 1, e, b);
        for (var i = s, j = s, k = m + 1; i <= e; ++i)
        {
            b[i] = this[(k > e || j <= m && this[j] < this[k]) ? j++ : k++];
        }
        for (var i = s; i <= e; ++i) this[i] = b[i];
    }

    Array.prototype.heapSort = function()
    {
        for (var i = 1; i < this.length; ++i)
        {
            for (var j = i, k = (j - 1) >> 1; k >= 0; j = k, k = (k - 1) >> 1)
            {
                if (this[k] >= this[j]) break;
                this.swap(j, k);
            }
        }
        for (var i = this.length - 1; i > 0; --i)
        {
            this.swap(0, i);
            for (var j = 0, k = (j + 1) << 1; k <= i; j = k, k = (k + 1) << 1)
            {
                if (k == i || this[k] < this[k - 1]) --k;
                if (this[k] <= this[j]) break;
                this.swap(j, k);
            }
        }
    }

    function generate()
    {
        var max = parseInt(txtMax.value), count = parseInt(txtCount.value);
        if (isNaN(max) || isNaN(count))
        {
            alert("个数和最大值必须是一个整数");
            return;
        }
        var array = [];
        for (var i = 0; i < count; ++i) array.push(Math.round(Math.random() * max));
        txtInput.value = array.join("\n");
        txtOutput.value = "";
    }

    function demo(type)
    {
        var array = txtInput.value == "" ? [] : txtInput.value.replace().split("\n");
        for (var i = 0; i < array.length; ++i) array[i] = parseInt(array[i]);
        var t1 = new Date();
        eval("array." + type + "Sort()");
        var t2 = new Date();
        lblTime.innerText = t2.valueOf() - t1.valueOf();
        txtOutput.value = array.join("\n");
    }
</script>

<body onload=generate()>
<table style="width:100%;height:100%;font-size:12px;font-family:宋体">
<tr>
    <td align=right>
        <textarea id=txtInput readonly style="width:100px;height:100%"></textarea>
    </td>
    <td width=150 align=center>
        随机数个数<input id=txtCount value=500 style="width:50px"><br><br>
        最大随机数<input id=txtMax value=1000 style="width:50px"><br><br>
        <button onclick=generate()>重新生成</button><br><br><br>& lt;br>
        耗时(毫秒)：<label id=lblTime></label><br><br><br><br>
        <button onclick=demo("bubble")>冒泡排序</button><br><br>
        <button onclick=demo("selection")>选择排序</button><br><br>
        <button onclick=demo("insertion")>插入排序</button><br><br>
        <button onclick=demo("shell")>谢尔排序</button><br><br>
        <button onclick=demo("quick")>快速排序(递归)</button><br><br>
        <button onclick=demo("stackQuick")>快速排序(堆栈)</button><br><br& gt;
        <button onclick=demo("merge")>归并排序</button><br><br>
        <button onclick=demo("heap")>堆排序</button><br><br>
    </td>
    <td align=left>
        <textarea id=txtOutput readonly style="width:100px;height:100%"></textarea>
    </td>
</tr>
</table>
</body>