《大话数据结构》读书笔记之冒泡排序和源码及优化算法源码

#include <stdio.h>
#define MAXSIZE 10

typedef struct
{
int r[MAXSIZE + 1];
int length;
}SqList;

void InitSqList(SqList *L)
{
printf("please input the length of the sqlist:\n");
scanf("%d",&(L->length));

printf("please input the values of the sqlist:\n");
for (int index = 0; index < L->length; index++)
{
scanf("%d", &(L->r[index]));
}

}

void PrintSqList(SqList L)
{
for (int index = 0; index < L.length; index++)
{
printf("%d\n", L.r[index]);
}

printf("\n");
}

void swap(SqList *L, int i, int j)
{
int tem = L->r[i];
L->r[i] = L->r[j];
L->r[j] = tem;
}
//貌似是冒泡排序，不正宗
void BubbleSort0(SqList *L)
{
int firstIndex;
int secondIndex;

for (firstIndex = 0; firstIndex < L->length - 1; firstIndex++)
{
for (secondIndex = firstIndex + 1; secondIndex < L->length; secondIndex++)
{
if (L->r[firstIndex] > L->r[secondIndex])				//值一大就往后移动，自然是升序
{
swap(L, firstIndex, secondIndex);
}
}
}
}
//传统的冒泡排序，选择了三个比较区间，基本思想是一样的
void BubbleSort(SqList *L)
{
int firstIndex;
int secondIndex;

for (firstIndex = 0; firstIndex < L->length; firstIndex++)
{
for (secondIndex = L->length - 1; secondIndex > firstIndex; secondIndex--)
{
if (L->r[secondIndex] < L->r[secondIndex - 1])
{
swap(L, secondIndex, secondIndex - 1);
}
}
}
/*
for (firstIndex = 0; firstIndex < L->length; firstIndex++)
{
for (secondIndex = 1; secondIndex < L->length - firstIndex; secondIndex++)
{
if (L->r[secondIndex - 1] < L->r[secondIndex])		//如果前面数据小于后面的数据，就将二个数据交换，前面数永远不比后面数小，所以是从大到小排
{
swap(L, secondIndex - 1, secondIndex);
}
}
}*/

/*
for (firstIndex = 0; firstIndex < L->length - 1; firstIndex++)
{
for (secondIndex = L->length - 2; secondIndex >= firstIndex; secondIndex--)
{
if (L->r[secondIndex] < L->r[secondIndex + 1])
{
swap(L, secondIndex, secondIndex + 1);
}
}
}*/
}

#define TRUE 1
#define FALSE 0
typedef int Status;

void BubbleSort2(SqList *L)
{
int firstIndex = L->length;
int secondIndex;
Status flag = TRUE;

while (flag)	//如果有一趟没有发生交换，说明排序已经完成
{
flag = FALSE;
for (secondIndex = 1; secondIndex < firstIndex; secondIndex++)
{
if (L->r[secondIndex - 1] < L->r[secondIndex])
{
swap(L, secondIndex - 1, secondIndex);
flag = TRUE;							//有交换说明没有完成排序
}
}
firstIndex--;
}

}

void BubbleSort3(SqList *L)
{
int index;
int flag = L->length;
int maxIndex;

while (flag > 0)
{
maxIndex = flag;
flag = 0;
for (index = 1; index < maxIndex; index++)
{
if (L->r[index - 1] < L->r[index])
{
swap(L, index - 1, index);
flag =  index;						//for循环结束，flag位置之后的数据必定已经有序了，记录下这位置，第二次只要从数
//组头部遍历到这个位置就可以了
}
}
}

}

int main()
{
SqList L;

InitSqList(&L);

BubbleSort3(&L);
printf("after sorting ,the sqlist is:\n");
PrintSqList(L);
return 0;
}