- 直接插入排序：
public void InsertSort(int[] a){
int length=a.length;
int insertNum;
for(int i=1; i<length;i++){
insertNum = a[i];
int j = i-1;
while(j>=0&&a[j]>insertNum){
a[j+1] = a[j];
j--;
}
a[j+1] = intsertNum;
}
}
