【数据结构】堆和树详解&&堆和二叉树的实现&&堆的top-k问题

#pragma once
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
typedef int HPDataType;
typedef struct Heap
{
	HPDataType* a;
	int size;
	int capacity;
}HP;
//初始化
void HPInit(HP* php);
//销毁
void HPDestroy(HP* php);
//交换
void Swap(HPDataType* p1, HPDataType* p2);
//向上调整
void AdjustUp(HPDataType* a, int child);
//插入(小堆)
void HPPush(HP* php, HPDataType x);
//向下调整
void AdjustDown(HPDataType* a, int size, int parent);
//删除(根节点)
void HPPop(HP* php);
//返回堆顶数据
int HPTop(HP* php);
//判空
bool HPEmpty(HP* php);
//返回数据个数
int HPSize(HP* php);

#define _CRT_SECURE_NO_WARNINGS 1
#include "Heap.h"\
//初始化
void HPInit(HP* php)
{
	assert(php);
	php->a = NULL;
	php->size = 0;
	php->capacity = 0;
}
//销毁
void HPDestroy(HP* php)
{
	assert(php);
	free(php->a);
	php->a = NULL;
	php->size = 0;
	php->capacity = 0;
}
//交换
void Swap(HPDataType* p1, HPDataType* p2)
{
	HPDataType tmp = *p1;
	*p1 = *p2;
	*p2 = tmp;
}
//向上调整
void AdjustUp(HPDataType* a, int child)
{
	int parent = (child - 1) / 2;
	while (child > 0)
	{
		if (a[child] < a[parent])
		{
			Swap(&a[child], &a[parent]);
			child = parent;
			parent = (child - 1) / 2;
		}
		else
			break;
	}
}
//插入(小堆)
void HPPush(HP* php, HPDataType x)
{
	assert(php);
	if (php->size == php->capacity)
	{
		int newcapacity = php->capacity == 0 ? 4 : php->capacity * 2;
		HPDataType* tmp = (HPDataType*)realloc(php->a, sizeof(HPDataType) * newcapacity);
		if (tmp == NULL)
		{
			perror("realloc fail");
			exit(-1);
		}
		php->a = tmp;
		php->capacity = newcapacity;
	}
	php->a[php->size] = x;
	php->size++;
	AdjustUp(php->a, php->size - 1);
}
//向下调整
void AdjustDown(HPDataType* a, int size, int parent)
{
	int child = parent * 2 + 1;
	while (child < size)
	{
		if ((child + 1) < size && a[child + 1] < a[child])
			child++;
		if (a[child] < a[parent])
		{
			Swap(&a[child], &a[parent]);
			parent = child;
			child = parent * 2 + 1;
		}
		else
			break;
	}
}
//删除(根节点)
void HPPop(HP* php)
{
	assert(php);
	assert(php->size > 0);
	Swap(&php->a[0], &php->a[php->size - 1]);
	php->size--;
	AdjustDown(php->a, php->size, 0);
}
//返回堆顶数据
int HPTop(HP* php)
{
	assert(php);
	assert(php->size > 0);
	return php->a[0];
}
//判空
bool HPEmpty(HP* php)
{
	assert(php);
	return php->size == 0;
}
//返回数据个数
int HPSize(HP* php)
{
	assert(php);
	return php->size;
}

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void Swap(int* p1, int* p2)
{
	int tmp = *p1;
	*p1 = *p2;
	*p2 = *p1;
}
void AdjustUp(int* a, int child)
{
	int parent = (child - 1) / 2;
	while (child > 0)
	{
		if (a[child] < a[parent])
		{
			Swap(&a[child], &a[parent]);
			child = parent;
			parent = (child - 1) / 2;
		}
		else
			break;
	}
}
void AdjustDown(int* a, int size, int parent)
{
	int child = parent * 2 + 1;
	while (child < size)
	{
		if (child + 1 < size && a[child + 1] < a[child])
		{
			++child;
		}
		if (a[child] < a[parent])
		{
			Swap(&a[child], &a[parent]);
			parent = child;
			child = parent * 2 + 1;
		}
		else
			break;
	}
}
void CreatNDate()
{
	//造数据
	int n = 10000000;
	srand(time(0));
	const char* file = "data.txt";
	FILE* fin = fopen(file, "w");
	if (fin == NULL)
	{
		perror("fopen error");
		return;
	}
	for (int i = 0; i < n; i++)
	{
		int x = (rand() + i) % 10000000;
		fprintf(fin, "%d\n", x);
	}
	fclose(fin);
}
void PrintTopK(const char* file, int k)
{
	FILE* fout = fopen(file, "r");
	if (fout == NULL)
	{
		perror("fopen error");
		return;
	}
	//建一个k个数的小堆
	int* minheap = (int*)malloc(sizeof(int) * k);
	if (minheap == NULL)
	{
		perror("malloc fail");
		return;
	}
	//读取前k个数
	for (int i = 0; i < k; i++)
	{
		fscanf(fout, "%d", &minheap[i]);
		//建小堆
		AdjustUp(minheap, i);
	}
	//读文件剩下的值
	int x = 0;
	while (fscanf(fout, "%d", &x) != EOF)
	{
		//与堆顶进行比较
		if (x > minheap[0])
		{
			//替代堆顶的值
			minheap[0] = x;
			//向下调整
			AdjustDown(minheap, k, 0);
		}
	}
	for (int i = 0; i < k; i++)
	{
		printf("%d ", minheap[i]);
	}
	printf("\n");
	fclose(fout);
}
int main()
{

	//CreatNDate();
	PrintTopK("data.txt", 5);
	return 0;
}