插入排序作为十大排序之一，是一种简单且稳定的排序算法
算法思想相对直观,可以联想自己平常打扑克牌，发牌时自己边摸牌边整理牌顺序的场景
算法思想：A[i] 与 A[i] 之前的元素 A[j逐个进行比较，如果 A[i]<A[j]，则交换，否则 j++，A[j] 往后移一位，直到指针 i=j 时 A[j] 停止移动，A[i] 往后移一位，A[j] 重新从 0 开始到 i，以此类推，直到 i 走到数组的最后一个位置为止
A[i]：序列的第 2 到最后一个数 范围：[1, length-1]
A[j]：序列的第 1 个到 第 i 个 范围：[ 1 , i ]
适用场景：数据量小、有序或者部分有序的数列
时间复杂度：O(n^2) 空间复杂度：O(1)
代码实现：
import java.util.Arrays;
/**
* Java十大排序之插入排序
* @author com
*
*/
public class Sorts {
public static void main(String[] args) {
int[] arr = {49,26,2,9,16,0,10,100,24};
System.out.println(Arrays.toString(insertSort(arr)));
}
public static int[] insertSort(int[] A) {
int length = A.length;
int temp = 0;
for(int i=1;i<length;i++) {
for(int j=0;j<i;j++) {
if(A[i]<A[j]) {
temp = A[i];
A[i] = A[j];
A[j] = temp;
}
}
//System.out.println(Arrays.toString(A));
}
return A;
}
}
运行结果：
[0, 2, 9, 10, 16, 24, 26, 49, 100]
原数据：
[49, 26, 2, 9, 16, 0, 10, 100, 24]
第 1 趟排序：i = 1，A[i] = 26；当 j = 0 时 ，A[i] < A[j]， A[i] 和 A[j] 互换，即 26和49互换
[26, 49, 2, 9, 16, 0, 10, 100, 24]
第 2 趟排序：
[2, 49, 26, 9, 16, 0, 10, 100, 24]
[2, 26, 49, 9, 16, 0, 10, 100, 24]
第 3 趟排序：
[2, 26, 49, 9, 16, 0, 10, 100, 24]
[2, 9, 49, 26, 16, 0, 10, 100, 24]
[2, 9, 26, 49, 16, 0, 10, 100, 24]
第 4 趟排序：
[2, 9, 26, 49, 16, 0, 10, 100, 24]
[2, 9, 26, 49, 16, 0, 10, 100, 24]
[2, 9, 16, 49, 26, 0, 10, 100, 24]
[2, 9, 16, 26, 49, 0, 10, 100, 24]
第 5 趟排序：
[0, 9, 16, 26, 49, 2, 10, 100, 24]
[0, 2, 16, 26, 49, 9, 10, 100, 24]
[0, 2, 9, 26, 49, 16, 10, 100, 24]
[0, 2, 9, 16, 49, 26, 10, 100, 24]
[0, 2, 9, 16, 26, 49, 10, 100, 24]
第 6 趟排序：
[0, 2, 9, 16, 26, 49, 10, 100, 24]
[0, 2, 9, 16, 26, 49, 10, 100, 24]
[0, 2, 9, 16, 26, 49, 10, 100, 24]
[0, 2, 9, 10, 26, 49, 16, 100, 24]
[0, 2, 9, 10, 16, 49, 26, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
第 7 趟排序：
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
第 8 趟排序：
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 26, 49, 100, 24]
[0, 2, 9, 10, 16, 24, 49, 100, 26]
[0, 2, 9, 10, 16, 24, 26, 100, 49]
[0, 2, 9, 10, 16, 24, 26, 49, 100]
最终结果：
[0, 2, 9, 10, 16, 24, 26, 49, 100]
