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hello-algo/codes/cpp/chapter_heap/heap.cpp

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/**
* File: heap.cpp
* Created Time: 2023-01-19
* Author: LoneRanger(836253168@qq.com)
*/
#include "../include/include.hpp"
void testPush(priority_queue<int> &heap, int val)
{
heap.push(val); // 元素入堆
cout << "\n元素 " << val << " 入堆后" << endl;
PrintUtil::printHeap(heap);
}
void testPop(priority_queue<int> &heap)
{
int val = heap.top();
heap.pop();
cout << "\n堆顶元素 " << val << " 出堆后" << endl;
PrintUtil::printHeap(heap);
}
int main()
{
/* 初始化堆 */
// 初始化小顶堆
// priority_queue<int, vector<int>, greater<int>> minHeap;
// 初始化大顶堆
priority_queue<int, vector<int>, less<int>> maxHeap;
cout << "\n以下测试样例为大顶堆" << endl;
/* 元素入堆 */
testPush(maxHeap, 1);
testPush(maxHeap, 3);
testPush(maxHeap, 2);
testPush(maxHeap, 5);
testPush(maxHeap, 4);
/* 获取堆顶元素 */
int peek = maxHeap.top();
cout << "\n堆顶元素为 " << peek << endl;
/* 堆顶元素出堆 */
testPop(maxHeap);
testPop(maxHeap);
testPop(maxHeap);
testPop(maxHeap);
testPop(maxHeap);
/* 获取堆大小 */
int size = maxHeap.size();
cout << "\n堆元素数量为 " << size << endl;
/* 判断堆是否为空 */
bool isEmpty = maxHeap.empty();
cout << "\n堆是否为空 " << isEmpty << endl;
/* 输入列表并建堆 */
// 时间复杂度为 O(n) ,而非 O(nlogn)
vector<int> input{1, 3, 2, 5, 4};
priority_queue<int, vector<int>, greater<int>> minHeap(input.begin(), input.end());
cout << "输入列表并建立小顶堆后" << endl;
PrintUtil::printHeap(minHeap);
return 0;
}