JS六种排序算法

   <p>// 冒泡排序</p>    <p>// 循环的最大值从length递减</p>    <p>// 基本就是每次循环只能排好最后一个 然后递减到第一个</p>    <pre>  <code class="language-javascript">function bubbleSort(){  var changedData = new Array();  var index = 0;      console.log("冒泡调用");      for (var j = a.length; j >0 ; j--) {          for (var i = 0; i < j; i++) {              if(a[i]>a[i+1]){                  var z = 0;                  z = a[i+1];                  a[i+1] = a[i];                  a[i] = z;              }              changedData[index] = a.toString();              index++;          }//one                  }//two      showDateChange(changedData);  }</code></pre>    <p>// 选择排序</p>    <p>// 外循环 j选取当前元素 到length-1</p>    <p>// 内循环 j+1开始 到length 逐个比较出最小值min</p>    <p>// 交换 min 和 a[j]</p>    <pre>  <code class="language-javascript">function selectionSort(){  var changedData = new Array();  var index = 0;      console.log("选择调用");      for (var j = 0; j < a.length-1; j++) {          var min = a[j];          var minIndex = j;          for (var i = j+1; i < a.length; i++) {              if(a[i] < min) {                  min = a[i];                  minIndex = i;              }          }//one          a[minIndex] = a[j];          a[j] = min;          //           changedData[index] = a.toString();          index++;      }//two      showDateChange(changedData);  }</code></pre>    <p>// 插入排序</p>    <p>// 从下标1开始 往后选择直到最后</p>    <p>// 每个选中的和他前面的所有比较</p>    <p>// 直到找到比他小的 排在他后面</p>    <p>// 相当于从1开始 每次都排好之前的i+1个 直到length</p>    <p>// 和冒泡相反</p>    <pre>  <code class="language-javascript">function insertionSort(){  var changedData = new Array();  var index = 0;      console.log("插入排序");      for (var j = 1; j < a.length; j++) {          var now = a[j];          var i = j - 1;          while(i>=0 && now<a[i]){              // 向后移数组              a[i+1] = a[i];              i--;          }//one          a[i+1] = now;          changedData[index] = a.toString();          index++;      }//two      showDateChange(changedData);  }</code></pre>    <p>// 希尔排序</p>    <p>// 间隔改变的插入排序</p>    <p>// 传统插入排序 比较前面的相邻对象</p>    <p>// 希尔排序比较前面的第h个对象 直到h间隔不存在更改</p>    <p>// 改变h 直到 h=1</p>    <pre>  <code class="language-javascript">function shellSort(){  var changedData = new Array();  var index = 0;      console.log("希尔排序");      var N = a.length;      var h = 1;      if (h < N/3) {          h = h*3 + 1;//设置间隔      }      while(h > 0){          for (var j = h; j < a.length; j++) {              for (var i = j;i >= h && a[i] < a[i-h]; i -= h) {                  var z;                  z = a[i];                  a[i] = a[i-h];                  a[i-h] = z;                  //                   changedData[index] = a.toString();                  index++;              }          }          h = (h-1)/3;//改变间隔      }      showDateChange(changedData);  }</code></pre>    <p>// 归并排序</p>    <p>// 数据分为 step为间隔的小数组</p>    <p>// 将小数组排序 step变大 直到为1/2个数组</p>    <p>// 将前后两个已排序的数组 再排序</p>    <pre>  <code class="language-javascript">function mergeSort(arr){  var changedData = new Array();      console.log("归并排序");      if (arr.length < 2) {          return;      }      var step = 1;      var left;      var right;      while(step < arr.length){          left = 0;          right = step;          while(right + step <= arr.length){              mergeArrays(arr,left,left+step,right,right+step);              left = right + step;              right = left + step;          }          if (right < arr.length) {              mergeArrays(arr,left,left+step,right,arr.length);          }          step *= 2;      }      function mergeArrays(arr,startLeft,stopLeft,startRight,stopRight){          var leftArray = new Array(stopLeft - startLeft +1);          var rightArray = new Array(stopRight - startRight +1);          k = startRight;          for (var i = 0; i < rightArray.length-1; i++) {              rightArray[i] = arr[k];              k++;          }          k = startLeft;          for (var i = 0; i < leftArray.length-1; i++) {              leftArray[i] = arr[k];              k++;          }          rightArray[rightArray.length-1] = Infinity;          leftArray[leftArray.length-1] = Infinity;          var m = 0;          var n = 0;          for (var k = startLeft; k < stopRight; k++) {              if (leftArray[m] <= rightArray[n]) {                  arr[k] = leftArray[m];                  m++;              }else{                  arr[k] = rightArray[n];                  n++;                  }          }          arr += "";//转化为字符串          changedData.push(arr);      }      showDateChange(changedData);  }</code></pre>    <p>// 快速排序</p>    <p>// 没实现可视化排序</p>    <pre>  <code class="language-javascript">function quickSort(){      console.log("快速排序");      function qSort(list){          if (list.length == 0) {              return list;          }          // 选取基数          var pivotIndex = Math.floor(list.length/2);          var pivot = list.splice(pivotIndex,1)[0];            var left = [];          var right = [];          for (var i = 0; i < list.length; i++) {              if (list[i] > pivot) {                  right.push(list[i]);              }else{                  left.push(list[i]);              }          }          // 递归 更换基数 并且排序其左右          return qSort(left).concat([pivot],qSort(right));      }      a = qSort(a);      showDate();  }</code></pre>    <p> </p>    <p>来自：https://segmentfault.com/a/1190000007013104</p>    <p> </p>