#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define MAXLENGTH 21

typedef struct 
{
	int key;
}Record;

typedef struct
{
	Record r[MAXLENGTH];
	int length;
}DataList;

void sort(DataList *list)
{
	printf("list length = %d\n",list->length);

	int i = 1;
	for(i=1;i<list->length;i++)
	{
		printf("list r[%d].key=%d \t",i,list->r[i].key);
	}

	printf("\n***********************************************\n");

	int j=0;
	for(i=1;i<list->length;i++)	//r[0]为监视哨所以从1开始
	{
		list->r[0].key = list->r[i].key;
		j=i-1;
		while(list->r[0].key <= list->r[j].key)
		{
			list->r[j+1] = list->r[j];
			j--;
		}
		list->r[j+1] = list->r[0];
	}

	i = 1;
	for(i=1;i<list->length;i++)
	{
		printf("list r[%d].key=%d \t",i,list->r[i].key);
	}
	printf("\n");

}

int main()
{
	DataList *list = (DataList *)malloc(1*sizeof(DataList));
	memset(list,0,sizeof(DataList));
	
	srand(time(0));

	int m = 0;
	int index = 1;
	for(m=0;m<20;m++)
	{
		int i = 0;
		i = rand() % 100;
		list->r[index].key = i;
		list->length++;
		index++;
	}

	sort(list);

	getchar();
}