上了算法课说到了归并排序记录一下:
#include<iostream>
using namespace std;
void mergeArrary(int arr[], int first, int mid, int last, int temp[])
{
int i = first, j = mid + 1;
int m = mid, n = last;
int k = 0;
while (i <= mid && j <= n)
{
if (arr[i] <= arr[j])
{
temp[k++] = arr[i++];
}
else
{
temp[k++] = arr[j++];
}
}
while (i <= mid)
{
temp[k++] = arr[i++];
}
while (j <= n)
{
temp[k++] = arr[j++];
}
for (i = 0; i < k; i++)
{
arr[first + i] = temp[i];
}
}
void mergesort(int arr[], int first, int last, int temp[])
{
if (first < last)
{
int mid = (first + last) / 2;
mergesort(arr, first, mid, temp);
mergesort(arr, mid + 1, last, temp);
mergeArrary(arr, first, mid, last, temp);
}
}
int main()
{
int arr[] = { 6, 3, 8, 5, 9, 2, 4, 1 };
int temp[8] = { 0 };
mergesort(arr, 0, 7, temp);
int i = 0;
for (i = 0; i < 8; i++)
{
cout << arr[i] << " ";
}
cout << endl;
system("pause");
return 0;
}