插入排序

package foo;

import java.util.Arrays;

public class Main {
    
    public static void insertionSort(int[] a, int len) {
        int in, out;
        int temp;
        for (out=1;out<len;++out) {
            temp = a[out];
            in = out;
            while (in>0&&a[in-1]>temp) {
                a[in] = a[in-1];
                --in;
            }
            a[in] = temp;
        }
    }
    
    public static void main(String[] args) throws Exception {
        int[] a = new int[]{3,2,1,5,4};
        insertionSort(a, a.length);
        System.out.println(Arrays.toString(a));
    }
}