/*
 * @Brief: 常见排序算法汇总
 * @Author: 
 * @Date: 2021-07-01 
*/
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>

using namespace std;

void printArray(int *a, int len){
    for(int i = 0; i < len; i++) cout << a[i] << " ";
    cout << endl << endl;
}

void bubbleSort(int *a, int len){
    for(int i = 0; i < len - 1; i++){

        for(int j = 0; j < len - i; j++){
            if(a[j] > a[j+1]) swap(a[j], a[j+1]);
        }
        
    }
}

void selectSort(int *a, int len){
    for(int i = 0; i < len; i++){
        int mi = i;
        for(int j = i; j < len; j++){
            if(a[j] < a[mi]) mi = j;
        }

        if(i != mi) swap(a[i], a[mi]);
    }
}

void insertionSort(int *a, int len){

    for(int i = 0; i < len; i++){
        int key = a[i];
        int j = i;
        while(j >= 1 && a[j - 1] > key) a[j] = a[j-1], j--;
        a[j] = key;
    }

}

void shellSort(int *a, int len){
    // cout << "原始数组" << endl;
    // printArray(a, len);

    for(int d = len / 2; d >= 1; d /= 2){

        // 插入排序
        for(int i = 0; i < len; i += d){
            int key = a[i];
            int j = i;
            while(j >= d && a[j-d] > key) a[j] = a[j-d], j -= d;
            a[j] = key;   
        }

        // cout << "d = " <<  d << " 排序结果" << endl;
        // printArray(a, len);

    }

}

void quickSort(int *a, int len, int l, int r){
    if(l >= r) return ;
    int x = a[l + (r - l) / 2];

    int i = l - 1, j = r + 1;
    while(i < j){
        while(a[++i] < x);
        while(a[--j] > x);
        if(i < j) swap(a[i], a[j]);
    }
    quickSort(a, len, l, j);
    quickSort(a, len, j + 1, r);
}

void mergeSort(int *a, int len, int l, int r){

    if(l >= r) return ;

    int mid = l + (r - l) / 2;
    mergeSort(a, len, l, mid);
    mergeSort(a, len, mid + 1, r);

    int i = l, j = mid + 1, k = 0;
    int *tmp = new int[r - l + 1];
    while(i <= mid && j <= r){
        if(a[i] < a[j]) tmp[k++] = a[i++];
        else tmp[k++] = a[j++]; 
    }

    // 处理尾巴
    while(i <= mid) tmp[k++] = a[i++];
    while(j <= r) tmp[k++] = a[j++];

    // 复制回原数组中
    for(i = l, k = 0; i <= r; i++, k++) a[i] = tmp[k];
    delete tmp;  // 回收内存
}

// 堆排序
namespace heapSort{

    int *heap = nullptr;
    int ss = 0;  // 堆的现有节点数  从下标是1的节点开始存
    int n = 0; // 数组长度

    void down(int u){
        // 小顶堆
        int t = u;
        if(u * 2 <= ss && heap[u * 2] < heap[t]) t = u * 2;
        if(u * 2 + 1 <= ss && heap[u * 2 + 1] < heap[t]) t = u * 2 + 1;
        if(t != u){
            swap(heap[t], heap[u]);
            down(t);
        }
    }

    void heapSort(int *a, int len){
        heap = new int[len + 5];
        n = len;
        for(int i = 0; i < len; i++) heap[++ss] = a[i];
        for(int i = n / 2; i ; i--) down(i);
        for(int i = 0; i < len; i++){
            a[i] = heap[1];
            heap[1] = heap[ss--];
            down(1);
        }
        delete heap;
    }
    
};

int main(){
    

    int a[10] = {8, 4, 2, 5, 7, 3, 1, 9, 0, 6};
    int len = 10;

    //bubbleSort(a, len);
    //selectSort(a, len);
    //insertionSort(a, len);
    //quickSort(a, len, 0, len - 1);
    //mergeSort(a, len, 0, len - 1);
    //shellSort(a, len);
    //heapSort::heapSort(a, len);

    printArray(a, len);
    
    return 0;
}