C++排序-2

5、归并排序

#include <vector>
#include <iostream>
#include <random>
#include <algorithm>

using namespace std;

void MergeSort(vector<int> &data, vector<int> &cdata, int p, int r);
void Merge(vector<int> &data, vector<int> &cdata, int p, int q, int r);

void MergeSort(vector<int> &data)
{
    vector<int> cdata(data.size());
    MergeSort(data, cdata, 0, data.size() - 1);
}

void MergeSort(vector<int> &data, vector<int> &cdata, int p, int r)
{
    if (p < r) {
        int q = (p + r) / 2;
        MergeSort(data, cdata, p, q);
        MergeSort(data, cdata, q + 1, r);
        Merge(data, cdata, p, q, r);
    }
}

void Merge(vector<int> &data, vector<int> &cdata, int p, int q, int r)
{
    for (int i = p; i <= r; ++i)
        cdata[i] = data[i];

    int i = p, j = q + 1, k = p;

    while (i <= q && j <= r) {
        if (cdata[i] <= cdata[j])
            data[k++] = cdata[i++];
        else
            data[k++] = cdata[j++];
    }

    while (i <= q)
        data[k++] = cdata[i++];
    while (j <= r)
        data[k++] = cdata[j++];
}


int main(int argc, char *argv[])
{
    vector<int> data1 = { 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 };
    vector<int> data2;

    default_random_engine dre(7);
    uniform_int_distribution<int> di(-100, 100);

    for (int i = 0; i < 50; ++i)
        data2.push_back(di(dre));

    MergeSort(data1);
    for (auto i : data1)
        cout << i << " ";
    cout << endl;

    MergeSort(data2);
    for (auto i : data2)
        cout << i << " ";
    cout << endl;
    return 0;
}

6、堆排序

#include <iostream>
#include <vector>
#include <random>

using namespace std;

inline int leftChild(int i)
{
    return 2 * i + 1;
}

void sink(vector<int> &data, int i, int n)
{
    int child;
    int tmp;
    for (tmp = data[i]; leftChild(i) < n; i = child) {
        child = leftChild(i);
        while (child != n - 1 && data[child] < data[child + 1]) 
            ++child;

        if (data[child] > tmp)
            data[i] = data[child];
        else 
            break;
    }
    data[i] = tmp;
}

void HeapSort(vector<int> &data)
{
    for (int i = data.size() / 2; i >= 0; --i)
        sink(data, i, data.size());

    for (int j = data.size() - 1; j > 0; --j) {
        swap(data[0], data[j]);
        sink(data, 0, j);
    }
}


int main(int argc, char* argv[])
{
    vector<int> data;

    default_random_engine dre;
    uniform_int_distribution<int> di(-50, 50);

    for (int i = 0; i < 50; ++i)
        data.push_back(di(dre));

    HeapSort(data);

    for (auto i : data)
        cout << i << " ";
    cout << endl;

    return 0;
}

 

 

7、快速排序

#include <iostream>
#include <vector>
#include <random>

using namespace std;

void InsertionSort(vector<int> &data, int left, int right)
{
    for (int i = left + 1; i <= right; ++i) {
        int tmp = data[i];
        int j = i - 1;
        while (j >= left && data[j] > tmp) {
            data[j + 1] = data[j];
            --j;
        }
        data[j + 1] = tmp;
    }
}

int mediant(vector<int> &data, int left, int right)
{
    int center = (left + right) / 2;

    if (data[left] > data[right])
        swap(data[left], data[right]);
    if (data[center] > data[right])
        swap(data[left], data[right]);
    if (data[left] > data[center])
        swap(data[left], data[center]);

    swap(data[center], data[right - 1]);
    return data[right - 1];
}

void QuickSort(vector<int> &data, int left, int right)
{
    if (left + 10 < right) {
        int pivot = mediant(data, left, right);

        int i = left, j = right - 1;
        for(;;) {    
            while (data[++i] < pivot) {}
            while (data[--j] > pivot) {}
            if (i < j)
                swap(data[i], data[j]);
            else
                break;
        }
        QuickSort(data, left, i - 1);
        QuickSort(data, i + 1, right);
    }
    else
        InsertionSort(data, left, right);
}

void QuickSort(vector<int> &data)
{
    QuickSort(data, 0, data.size() - 1);
}

int main(int argc, char *argv[])
{
    vector<int> data;

    default_random_engine dre;
    uniform_int_distribution<int> di(-100, 100);

    for (int i = 0; i < 50; ++i)
        data.push_back(di(dre));

    QuickSort(data);

    for (auto i : data)
        cout << i << " ";
    cout << endl;
    return 0;
}