常见排序算法的js实现

常见排序算法的js实现
冒泡排序

<script type="text/javascript">
		var a = [9, 6, 7, 67, 8];
		for(var i = 0;i < a.length - 1;i++) {
			for (var j = 0;j < a.length - 1-i;j++){
				if (a[j] > a[j+1]){
					var temp = a[j];
					a[j] = a[j+1];
					a[j+1] = temp;
			}
		}

		}
		console.log(a);
	

	</script>

选择排序

<script type="text/javascript">

		var a = [9, 6, 7, 67, 8];
		//实现方法一
		for(var i = 0;i < a.length - 1;i++) {
			var min = i;
			for (j = i + 1;j < a.length; j++){
				if (a[min] > a[j]){
					min = j;
				}
			}
			if (min !== i){
				var temp = a[min];
				a[min] = a[i];
				a[i] = temp;
			}
		}
		console.log(a);


		//实现方法二
		for (var i = 0; i < a.length - 1; i++){
			for (j = i + 1; j < a.length; j++){
				if (a[i] > a[j]){
					var temp = a[i];
					a[i] = a[j];
					a[j] = a[i];
				}
			}
		}
		console.log(a);
	</script>

插入排序

<script>
        function insertionSort(arr) {
            for (var i = 1; i < arr.length; i++) {
                var preIndex = i;
                var current = arr[i];
                while (preIndex > 0 && arr[preIndex - 1] > current) {
                    arr[preIndex] = arr[preIndex - 1];
                    preIndex--;
                }
                arr[preIndex] = current;
            }
            return arr;
        }

        var array = [1, 2, 4, 5, 6, 3, 5, 0, 38]
        console.log(insertionSort(array))
    </script>

快速排序

<script type="text/javascript">
		var arry = [2, 6, 98, 45, 34, 76, 34, 49, 88, 99, 709, 21, 65]

		function quickSort(arry) {
			if(arry.length <= 1){
				return arry
			}
			var centerIndex = Math.floor(arry.length/ 2);
			var center = arry.splice(centerIndex, 1);
			var left = [];
			var right = [];
			for(i = 0; i < arry.length; i++) {
				if(arry[i] < center) {
					left.push(arry[i])
				} else {
					right.push(arry[i])
				}
			}
				return quickSort(left).concat(center, quickSort(right))
		}

		arr = quickSort(arry)
		console.log(arr)
	</script>

希尔排序

<script>
        function shell(arr) {
            len = arr.length;
            // 初始化间隔
            grap = Math.floor(len / 2);
            while (grap >= 1) {
                for (var i = grap; i < len; i++) {
                    temp = arr[i];
                    pre = i;
                    while (pre - grap >= 0 && arr[pre - grap] > temp) {
                        arr[pre] = arr[pre - grap];
                        pre -= grap;
                    }
                    arr[pre] = temp;
                }
                grap = Math.floor(grap / 2)
            }
            return arr
        }

        var array = [1, 2, 4, 5, 6, 3, 5, 0, 38]
        console.log(shell(array))
    </script>