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

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/**
* File: heap.cpp
* Created Time: 2023-01-19
* Author: LoneRanger(836253168@qq.com)
*/
#include "../utils/common.hpp"
void testPush(priority_queue<int> &heap, int val) {
heap.push(val); // Push the element into heap
cout << "\nAfter element " << val << " is added to the heap" << endl;
printHeap(heap);
}
void testPop(priority_queue<int> &heap) {
int val = heap.top();
heap.pop();
cout << "\nAfter the top element " << val << " is removed from the heap" << endl;
printHeap(heap);
}
/* Driver Code */
int main() {
/* Initialize the heap */
// Initialize min-heap
// priority_queue<int, vector<int>, greater<int>> minHeap;
// Initialize max-heap
priority_queue<int, vector<int>, less<int>> maxHeap;
cout << "\nThe following test case is for max-heap" << endl;
/* Push the element into heap */
testPush(maxHeap, 1);
testPush(maxHeap, 3);
testPush(maxHeap, 2);
testPush(maxHeap, 5);
testPush(maxHeap, 4);
/* Access heap top element */
int peek = maxHeap.top();
cout << "\nTop element of the heap is " << peek << endl;
/* Pop the element at the heap top */
testPop(maxHeap);
testPop(maxHeap);
testPop(maxHeap);
testPop(maxHeap);
testPop(maxHeap);
/* Get heap size */
int size = maxHeap.size();
cout << "\nNumber of elements in the heap is " << size << endl;
/* Determine if heap is empty */
bool isEmpty = maxHeap.empty();
cout << "\nIs the heap empty " << isEmpty << endl;
/* Enter list and build heap */
// Time complexity is O(n), not O(nlogn)
vector<int> input{1, 3, 2, 5, 4};
priority_queue<int, vector<int>, greater<int>> minHeap(input.begin(), input.end());
cout << "After inputting the list and building a min-heap" << endl;
printHeap(minHeap);
return 0;
}