js常用排序实现,参考代码如下
<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:12pxfont-family:宋体">
<tr>
<td align=right>
<textarea id=txtInput readonly style="width:100pxheight: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><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>
<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:100pxheight:100%"></textarea>
</td>
</tr>
</table>
</body>
冒泡排序的原理就是讲两个相邻的元素进行比较,数值大的元素就会往后排就是换到走遍,而我们依次比较并把大数放在后面依次循环,那么最大的元素就会排在最后边,注意:在排完一次之后最后面的数已经是最大的了所以我们并不需再再次比较最后一个元素,也就是比较的次数以此减少。
var arr=[4,2,7,2,5,8,0,4,5,7,3,8,9]
冒泡排序
i 的目的是做多少轮的 比较 j和j+1是前后数据比较
var arr=[4,1,7,2]
i==0
arr[i]=4
j=0 arr[j]=4 arr[j+1]=1 4,1,7,2---->1,4,7,2
j=1 arr[j]=4 1,4,7,2--->1,4,7,2
j=2 arr[j]=7 1,4,7,2--->1,4,2,7
### j=3 arr[j]=7 arr[j+1]不存在 因为j+1超过数组的长度,所以j必须是长度-1
i==1
j==0 arr[j]=1 1,4,2,7--->1,4,2,7
j==1 arr[j]=4 1,4,2,7--->1,2,4,7
###j==2 上面一次循环中放在最后的是最大的,所以不需要循环到2
i==2
j=0 arr[j]=1 1,2,4,7-->1,2,4,7
function sorts(arr){
var len=arr.length-1
for(var i=0i<leni++){
for(var j=0j<len-ij++){
if(arr[j]>arr[j+1]){
// if(arr[j+1]-arr[j]<0)
var temp=arr[j+1]
arr[j+1]=arr[j]
arr[j]=temp
}
}
}
}
sorts(arr)
console.log(arr)