堆排序

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堆排序

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#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

void push_down(vector<int> &heap, int size, int u) {
    int t = u, left = u * 2, right = u * 2 + 1;
    if (left <= size && heap[left] > heap[t])   t = left;
    if (right <= size && heap[right] > heap[t])     t = right;
    if (t != u) {
        swap(heap[u], heap[t]);
        push_down(heap, size, t);
    }
}

void push_up(vector<int> &heap, int u) {
    while (u / 2 && heap[u / 2] < heap[u]) {
        swap(heap[u / 2], heap[u]);
        u /= 2;
    }
}

void heap_sort(vector<int> &q, int n) {
    int size = n;
    for (int i = 1; i<=n; i++)  push_up(q, i);

    for (int i = 1; i<=n; i++) {
        swap(q[1], q[size]);
        size --;
        push_down(q, size, 1);
    }
}

void insert(vector<int> &heap, int size, int x) {
    heap[ ++ size] = x;
    push_up(heap, x);
}

void remove_top(vector<int> &heap, int &size) {
    heap[1] = heap[size];
    size -- ;
    push_down(heap, size, 1);
}

int main() {
    vector<int> q;
    int n;
    cin >> n;
    q.resize(n+1);
    for (int i = 1; i<=n; i++)  cin >> q[i];
    heap_sort(q, n);
    for (int i = 1; i<=n; i++)  cout << q[i] << " " ;   cout << endl;
    return 0;
}