排序

//选择排序
void SelectSort(int *array, int size)
{
    for (int idx = 0; idx < size; ++idx)
    {
        int min = idx ;//假定第一个元素最小
        int tmp = idx + 1;//标记第二个元素
        while (tmp < size)//寻找最小的元素
        {
            if (array[tmp] < array[min])
            {
                min = tmp;
            }
            tmp++;
        }
        if (idx != min)
        {
            std::swap(array[min], array[idx]);
        }
    }
}

//冒泡排序
void BubbleSort(int* array, int size)
{
    int flag = 1;
    int  count = 0;
    for (int idx = 0; idx < size - 1; ++idx)//控制数据向后遍历
    {
        for (int jx = 0; jx < size - idx - 1; ++jx)//两个数进行比较
        {
            if (array[jx]>array[jx + 1])
            {
                std::swap(array[jx], array[jx + 1]);
                flag = 0;
            }
            count++;//标记比较次数
        }
        if (flag == 1)//有序的不进行比较
        {
            break;
        }
    }
}

//递归归并排序
void Merge(int *array, int *temp,int left, int mid, int right)//归并
{
    int begin1 = left;//标记最左边的节点
    int end1 = mid;//标记中间的节点
    int begin2 = mid+1;//
    int end2 = right;
    int index = left;
    while (begin1 <= end1 && begin2 <= end2)
    {
        if (array[begin1] < array[begin2])
        {
            temp[index++] = array[begin1++];
        }
        else
        {
            temp[index++] = array[begin2++];
        }
    }
    while (begin1 <= end1)
    {
        temp[index++] = array[begin1++];
    }
    while (begin2 <= end2)
    {
        temp[index++] = array[begin2++];
    }
}
void _MergeSort(int *array,int *temp, int left, int right)
{
    if (left < right)
    {
        int mid = left + ((right - left) >> 1);
        _MergeSort(array, temp, left, mid);
        _MergeSort(array,temp, mid + 1, right);
        Merge(array, temp,left, mid, right);
        memcpy(array + left, temp + left, sizeof(array[0])*(right - left + 1));
    }
}
void MergeSort(int *array, int size)
{
    int *temp = new int [size];
    if (NULL != temp)
    {
        _MergeSort(array, temp, 0, size - 1);
        delete[]temp;
    }
}

//非递归归并排序
void MergeSortNor(int *array, int size)
{
    int* temp = new int[size];
    int left = 0;
    int right = size - 1;
    int gap = 1;
    while (gap < size)
    {
        for (size_t idx = 0; idx < size; idx += 2 * gap)
        {
            left = idx;
            int mid = idx + gap - 1;
            right = mid + gap;
            if (mid >= size)
            {
                mid  = size - 1;
            }
            if (right >= size)
            {
                right = size - 1;
            }
            Merge(array, temp, left, mid, right);//归并
        }
        memcpy(array, temp, size*sizeof(int));
        gap++;
    }
    delete[]temp;
}

//打印排序后的序列
void printfSort(int arr[], int count)
{
    for (int idx = 0; idx < count; ++idx)
    {
        cout << arr[idx] << " ";
    }
    cout << endl;
}
void FuntTest()
{
    //int array[] = { 1 };
    int array[] = { 21, 25, 49, 25, 0, 16 };
    //int array[] = { 7, 3, 2, 0, 1, 4 };
    //int array[] = { 2, 3, 5, 7, 9, 0, 1, 6, 4, 8 };
    int count = sizeof(array) / sizeof(array[0]);
    cout << count << endl;
    printfSort(array, count);
    //BubbleSort(array, count);//ok
    //SelectSort(array, count);//ok
    //InsertSort(array, count);
    //MergeSort(array, count);//递归归并排序
    //MergeSortNor(array, count);非递归归并排序
    printfSort(array,count);
}
int main()
{
    FuntTest();
    system("pause");
    return 0;
}