【数据结构】堆的实现和堆排序--TOP-K问题

#define _CRT_SECURE_NO_WARNINGS 1
#pragma once
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <stdbool.h>

typedef int HPDataType;

typedef struct Heap
{
	HPDataType* a;
	int size;
	int capacity;
}HP;

//堆的初始化
void HPInit(HP* php);

//堆的销毁
void HPDestroy(HP* php);

//堆的插入
void HPPush(HP* php, HPDataType x);

//堆的删除
void HPPop(HP* php);

//取堆顶的数据
HPDataType HPTop(HP* php);

// 堆的数据个数
int HPsize(HP* php);

//堆的判空
bool HPEmpty(HP* php);

//堆的初始化
void HPInit(HP* php)
{
	assert(php);
	php->a = NULL;
	php->size = php->capacity = 0;
}
//堆的销毁
void HPDestroy(HP* php)
{
	assert(php);
	free(php->a);
	php->a = NULL;
	php->size = php->capacity = 0;
}

//堆的插入
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, newcapacity * sizeof(HPDataType));
		if (tmp == NULL)
		{
			perror("realloc fail");
			return;
		}
		php->a = tmp;
		php->capacity = newcapacity;
	}
	php->a[php->size] = x;
	php->size++;
    //向上调整
	AdjustUp(php->a, php->size - 1);
}

void Swap(HPDataType* p1, HPDataType* p2)
{
	HPDataType tmp = *p1;
	*p1 = *p2;
	*p2 = tmp;
}
//向上调整
void AdjustUp(HPDataType* a, int child)
{
	//初始条件
	//中间过程
	//结束条件
	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;
		}
	}

}

//堆的删除
void HPPop(HP* php)
{
	assert(php);
	assert(php->size > 0);
	Swap(&php->a[0], &php->a[php->size - 1]);
	php->size--;
    //向下调整
	AdjustDown(php->a, php->size, 0);
}

//向下调整
void AdjustDown(HPDataType* a, int n, int parent)
{
	//先假设左孩子
	int child = parent * 2 + 1;
	while (child < n)//child >= n说明孩子不存在，调整到叶子了
	{
		//找出小的那个孩子
		if (child + 1 < n && a[child + 1] < a[child])//这里child+1是判断是否有右孩子
		{
			++child;
		}
		if (a[child] < a[parent])
		{
			Swap(&a[child], &a[parent]);
			parent = child;
			child = parent * 2 + 1;
		}
		else
		{
			break;
		}
	}
}

//取堆顶的数据
HPDataType HPTop(HP* php)
{
	return php->a[0];
}
// 堆的数据个数
int HPsize(HP* php)
{
	return php->size;
}
//堆的判空
bool HPEmpty(HP* php)
{
	assert(php);
	return php->size == 0;
}

void TestHeap1()
{
	int a[] = {4,2,8,1,5,6,9,7};
	HP hp;
	HPInit(&hp);
	for (size_t i = 0; i < sizeof(a) / sizeof(int); i++)
	{
		HPPush(&hp,a[i]);
	}
	int i = 0;
	while (!HPEmpty(&hp))
	{
		printf("%d ", HPTop(&hp));
		HPPop(&hp);
	}
	HPDestroy(&hp);
}

void TestHeap2()
{
	int a[] = { 4,2,8,1,5,6,9,7 };
	HeapSort(a, sizeof(a) / sizeof(int));
}
void HeapSort(int* a, int n)
{
	//降序 建小堆
	//升序 建大堆
	for (int i = 1; i < n; i++)
	{
		AdjustUp(a, i);

	}
	//O(N*logN)
	int end = n - 1;
	while (end > 0)
	{
		Swap(&a[0], &a[end]);
		AdjustDown(a, end, 0);
		--end;
	}
}

void TestHeap2()
{
	int a[] = { 4,2,8,1,5,6,9,7 };
	HeapSort(a, sizeof(a) / sizeof(int));
}
void HeapSort(int* a, int n)
{
	for (int i = (n - 1 - 1) / 2; i < n; i++)
	{
		AdjustDown(a, n, i);
	}
	//O(N*logN)
	int end = n - 1;
	while (end > 0)
	{
		Swap(&a[0], &a[end]);
		AdjustDown(a, end, 0);
		--end;
	}
}

void CreateNDate()
{
	//造数据
	int n = 100000;
	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 TestHeap3()
{
	int k;
	printf("请输入k>:");
	scanf("%d", &k);
	int* kminheap = (int*)malloc(sizeof(int) * k);
	if (kminheap == NULL)
	{
		perror("malloc fail");
		return;
	}
	const char* file = "data.txt";
	FILE* fout = fopen(file, "r");
	if (fout == NULL)
	{
		perror("fopen error");
		return;
	}
	//读取文件中前k个数
	for (int i = 0; i < k; i++)
	{
		fscanf(fout, "%d", &kminheap[i]);
	}
	//建k个数的小堆
	for (int i = (k - 1 - 1) / 2; i >= 0; i--)
	{
		AdjustDown(kminheap, k, i);
	}
	
	//读取剩下的N-k个数
	int x = 0;
	while (fscanf(fout, "%d", &x) > 0)
	{
		if (x > kminheap[0])
		{
			kminheap[0] = x;
			AdjustDown(kminheap, k, 0);
		}
	}
	printf("最大前%d个数：", k);
	for (int i = 0; i < k; i++)
	{
		printf("%d ", kminheap[i]);
	}
	printf("\n");
}