内部排序

void SelectSort(int *a,int n)
{
for (int i = 0; i < n - 1; i++)
{
int flag = -1;
for (int j = i + 1; j < n; j++)
{
if (a[i] > a[j])
{
flag = j;
}
}
if (flag != -1)
{
int temp = a[i];
a[i] = a[flag];
a[flag] = temp;
}
}
}
void InsertSort(int *a, int n)
{
int j;
for (int i = 1; i < n; i++)
{
int temp = a[i];
for (j = i-1; j >= 0; j--)
{

if (temp<a[j])
{
a[j+1] = a[j];
}
else
{
break;
}
}
a[j+1] = temp;
}
}
void BubbleSort(int *a, int n)
{
for (int i = 0; i < n - 1; i++)
{
for (int j = 0; j < n - i-1; j++)
{
if (a[j]>a[j + 1])
{
int temp = a[j];
a[j] = a[j + 1];
a[j + 1] = temp;
}

}
}
}
void DoubleBubbleSort(int *a, int n)
{
int t = 0;
int s = n;
while (t < n / 2&&s>n/2)
{
for (int i = t; i < s-1; i++)
{
if (a[i]>a[i + 1])
{
int temp = a[i];
a[i] = a[i + 1];
a[i + 1] = temp;
}
}
s--;
for (int j = s; j > t; j--)
{
if (a[j] < a[j - 1])
{
int temp = a[j];
a[j] = a[j - 1];
a[j - 1] = temp;
}
}
t++;
}
}
void Merge(int *a, int begin, int mid, int end)
{
int n1 = 0;
int n2 = 0;
n1 = mid - begin + 1;
n2 = end - mid;
int *before = new int[n1];
int *after = new int[n2];
int i = 0;
int j = 0;
int k = begin;
for (i = 0; i < n1; i++)
{
before[i] = a[k];
k++;
}
for (j = 0; j < n2; j++)
{
after[j] = a[k];
k++;
}
i = 0;
j = 0;
for (k = begin;i<n1&&j<n2; k++)
{
if (before[i]>after[j])
{
a[k] = after[j];
j++;
}
else
{
a[k] = before[i];
i++;
}
}
if (i < n1)
while (i < n1)
{
a[k] = before[i];
i++;
k++;
}
else
while (j < n2)
{
a[k] = after[j];
j++;
k++;
}
}
void MergeSort(int *a, int begin, int end)
{
if (begin < end)
{
int mid = (begin + end) / 2;
MergeSort(a, begin, mid);
MergeSort(a, mid + 1, end);
Merge(a, begin, mid, end);
}
}
void QuickSort(int *a, int left,int right)
{
if (left > right)
return;
int x = a[left];
int i = left;
int j = right;
while (i < j)
{
while (i<j&&a[j] > x)
j--;
if (i < j)
a[i++] = a[j];
while (i<j&&a[i] < x)
i++;
if (i < j)
a[j--] = a[i];
}
a[i] = x;
QuickSort(a,left,i-1);
QuickSort(a,i+1, right);
}
void ShellSort(int *a, int n)
{
for (int h = n / 2; h > 0; h /= 2)
{
for (int i = h; i < n; i++)
{
int temp = a[i];
int j;
for (j = i - h; j >= 0; j -= h)
{
if (a[j]>a[i])
a[j + h] = a[j];
else
break;
}
a[j + h] = temp;
}
}
}
void Heapfy(int A[], int idx, int max)      //建立最大堆
{
int left = idx * 2 + 1;
int right = left + 1;

int largest = idx;

if (left<max&&A[left]>A[idx]){ largest = left; }

if (right<max&&A[largest]<A[right]){ largest = right; }

if (largest != idx)
{
int temp = A[largest];
A[largest] = A[idx];
A[idx] = temp;
Heapfy(A, largest, max);

}
}

void HeapSort(int A[], int ll)
{
int len = ll;
for (int i = len / 2 - 1; i >= 0; --i)
{
Heapfy(A, i, len);
}
for (int i = len - 1; i >= 1; --i)
{
int temp = A[0];
A[0] = A[i];
A[i] = temp;
Heapfy(A, 0, i);
}
}
int main()
{
int a[] = { 3, 2, 5, 1, 3, 7, 6, 8 };
int n = sizeof(a) / sizeof(a[0]);
//DoubleBubbleSort(a, n);
//MergeSort(a, 0, n-1);
//QuickSort(a, 0, n - 1);
//ShellSort(a, n);
HeapSort(a, n);
for (int i = 0; i < n; i++)
{
cout << a[i] << '\t';
}
getchar();
}