问 ChatGPT 关于GPT的事情：扩展篇

目录

1.堆排序 

2.top-k问题

1.堆排序 

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<assert.h>
typedef int HPDataType;

//交换两个节点
void Swap(HPDataType* p1, HPDataType* p2)
{
	assert(p1 && p2);
	HPDataType tmp = *p1;
	*p1 = *p2;
	*p2 = tmp;
}

//向下调整算法
void AdjustDown(HPDataType* a, int n, int parent)
{
	assert(a);
	int  maxchild = parent * 2 + 1;
	while (maxchild < n)
	{
		//找到左右孩子中的较大者
		if (maxchild + 1 < n && a[maxchild] < a[maxchild + 1])
		{
			maxchild = maxchild + 1;//更新最大孩子
		}
		if (a[parent] < a[maxchild])
		{
			Swap(&a[parent], &a[maxchild]);
			//更新父子节点
			parent = maxchild;
			maxchild = parent * 2 + 1;
		}
		//当父子满足大堆关系时，不进行交换
		else
		{
			break;
		}
	}
}

//向上调整算法
void AdjustUp(HPDataType* a, int child)
{
	assert(a);
	int parent = (child - 1) / 2;
	while (child > 0)
	{
		//大堆
		if (a[parent] < a[child])
		{
			Swap(&a[parent], &a[child]);
			child = parent;
			parent = (child - 1) / 2;
		}
		else
		{
			break;
		}
	}
}

void HeapSort(HPDataType* a, HPDataType n)
{
	//向上调整建大堆
	int  i = 0;
	for (i = n - 1; i >= 0; i--)
	{
		AdjustUp(a, i);
	}
	//选数
	i = 1;
	while (i < n)
	{
		Swap(&a[0], &a[n - i]);
		AdjustDown(a, n - i, 0);
		i++;
	}
}

int main()
{
	HPDataType a[] = { 4,1,7,8,15,34,19,27,25,65 };
	int len = sizeof(a) / sizeof(a[0]);

	HeapSort(&a, len);
	//打印
	for (int i = 0; i < len; i++)
	{
		printf("%d ", a[i]);
	}

	return 0;
}

2.top-k问题

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include <time.h>
#include<assert.h>
#include<stdlib.h>
typedef int HPDataType;

//交换两个节点
void Swap(HPDataType* p1, HPDataType* p2)
{
	assert(p1 && p2);
	HPDataType tmp = *p1;
	*p1 = *p2;
	*p2 = tmp;
}

//向下调整算法
void AdjustDown(HPDataType* a, int n, int parent)
{
	assert(a);
	int  maxchild = parent * 2 + 1;
	while (maxchild < n)
	{
		//找到左右孩子中的较大者
		if (maxchild + 1 < n && a[maxchild] < a[maxchild + 1])
		{
			maxchild = maxchild + 1;//更新最大孩子
		}
		if (a[parent] < a[maxchild])
		{
			Swap(&a[parent], &a[maxchild]);
			//更新父子节点
			parent = maxchild;
			maxchild = parent * 2 + 1;
		}
		//当父子满足大堆关系时，不进行交换
		else
		{
			break;
		}
	}
}

//向上调整算法
void AdjustUp(HPDataType* a, int child)
{
	assert(a);
	int parent = (child - 1) / 2;
	while (child > 0)
	{
		//大堆
		if (a[parent] < a[child])
		{
			Swap(&a[parent], &a[child]);
			child = parent;
			parent = (child - 1) / 2;
		}
		else
		{
			break;
		}
	}
}

//创建数据文件
void CreateDataFile(const char* filename, int N)
{
	FILE* fin = fopen(filename, "w");
	if (fin == NULL)
	{
		perror("fopen fail");
		return;
	}
	srand(time);

	for (int i = 0; i < N; i++)
	{
		fprintf(fin, "%d\n", rand()%100);//产生100以内的随机数
	}
	fclose(fin);
}

void PrintTopK(const char* filename, int k)
{
	assert(filename);
	FILE* fout = fopen(filename, "r");
	if (fout == NULL)
	{
		perror("fopen fail");
		return;
	}
	//文件读取成功
	//为堆开辟空间
	int* minHeap = (int*)malloc(sizeof(int) * k);
	if (minHeap == NULL)
	{
		perror("malloc fail");
		return;
	}
	//读取前k个数到为堆开辟的空间中
	for (int i = 0; i < k; i++)
	{
		fscanf(fout, "%d", &minHeap[i]);
	}

	//前k个数建小堆.向上调整算法
	for (int i = k - 1; i >= 0; --i)
	{
		AdjustUp(minHeap, i);
	}

	//依次访问后N-k个数
	int val = 0;
	while (fscanf(fout, "%d", &val) != EOF)
	{
		//出现比k个数中最小数大的数，替换并向下调整
		if (val > minHeap[0])
		{
			minHeap[0] = val;
			AdjustDown(minHeap, k, 0);
		}
	}
	//打印前k个数
	for (int i = 0; i < k; i++)
	{
		printf("%d ", minHeap[i]);
	}
	free(minHeap);
	fclose(fout);

}

int main()
{
	const char* filename = "Data.text";
	int N = 100;
	int k = 10;
	//CreateDataFile(filename, N);
	PrintTopK(filename, k);

	return 0;
}