技術標籤：資料結構_基礎

原題

點此路徑1

題目分析

本題主要考察的是堆演算法的理解，可以按照課本（高等教育出版社-陳越-《資料結構》）P146中的堆插入演算法構件。
值得一提的是課本提出了兩種堆建立演算法，P146的插入演算法，P150中更快的構件演算法。上述兩種演算法得到的結果不相同，並且後者的速度更快。按照樣例輸出應該是使用前者。

程式碼

#include <iostream>
#include <algorithm>
#include <vector>
#include <list>
#include <string>
#include
 
 <array>

using namespace std;

class Heap;
typedef Heap *PHeap;

class Heap
{
public:
    int Size()
    {
        //return static_cast<int>(data.size()) - 1;
		return size;
    }

    int Data(int index)
    {
        return data[index];
    }

    void Swap(int left, int right)
    {
        std::
 
swap(data[left], data[right]);
    }

    int Top()
    {
        return data[1];
    }

    int Bottom()
    {
        //return data.back();
		return data[Size()];
    }

    bool IsEmpty()
    {
        return !Size();
    }

    void Print(int index)
    {
        while (index <= Size())
        {
 

            if (index == Size())
                cout << data[index] << endl;
            else
                cout << data[index] << " ";
            index++;
        }
    }

	void push_back(int value)
    {
		data[++size] = value;
    }

	void pop_back()
    {
		--size;
    }

    void Print2Root(int index)
    {
        while (index != -1)
        {
            auto father = FatherIndex(index);
            if (father == -1)
                cout << data[index] << endl;
            else
                cout << data[index] << " ";
            index = father;
        }
    }

    int LeftIndex(int index)
    {
        auto tmp = index * 2;
        if (tmp > Size())
            return -1;
        else
            return tmp;
    }

    int RightIndex(int index)
    {
        auto tmp = index * 2 + 1;
        if (tmp > Size())
            return -1;
        else
            return tmp;
    }

    int FatherIndex(int index)
    {
        if (index == 1)
            return -1;
        return index / 2;
    }

    Heap()
    {
        //data.push_back(0);
		data[0] = 0;
    }
	
    // vector<int> data;
	int data[1001];
	size_t size=0;
};

void Insert(PHeap heap, int v)
{
    heap->push_back(v);
    auto now = heap->Size();
    for (auto father = heap->FatherIndex(now); father != -1; now = father, father = heap->FatherIndex(now))
    {
        if (heap->Data(father) > heap->Data(now))
            heap->Swap(father, now);
        else
            break;
    }
}

void CheckHeap(PHeap heap, int index)
{
    auto parent = index;
    for (auto kid = heap->LeftIndex(parent); kid != -1; parent = kid, kid = heap->LeftIndex(parent))
    {
        auto right = heap->RightIndex(parent);
        if (right != -1 && heap->Data(kid) > heap->Data(right))
            kid = right;
        if (heap->Data(parent) > heap->Data(kid))
            heap->Swap(kid, parent);
        else
            break;
    }
}

int DeleteMin(PHeap heap)
{
    if (heap->IsEmpty())
        return -1;
    auto top = heap->Top();
    heap->data[1] = heap->Bottom();
    heap->pop_back();

    CheckHeap(heap, 1);

    return top;
}

void ConstructHeap(PHeap heap)
{
    if (heap->IsEmpty() || heap->Size() == 1)
        return;
    for (auto i = heap->Size() / 2; i > 0; i--)
        CheckHeap(heap, i);
}

int main()
{
    int n, outSum;
    cin >> n >> outSum;
    Heap heap;
    for (auto i = 0; i < n; i++)
    {
        int tmp;
        cin >> tmp;
        //heap.data.push_back(tmp);
        Insert(&heap, tmp);
    }
    //ConstructHeap(&heap);
    vector<int> outIndex;
    for (auto i = 0; i < outSum; i++)
    {
        int tmp;
        cin >> tmp;
        heap.Print2Root(tmp);
    }

    system("pause");
    return 0;
}