归并排序

归并排序，将两个顺序序列合并成一个顺序序列的方法。

int main()
{
cout << "hello" << endl;
int a[] = { 0,23,47,81,95,7,14,39,55,62,74 };//0占位不用
int b[11] = { 0 };//用来装归并后的数组

Merge(a, b, 1, 4, 10);//1-4,第一个数组的位置
for (int i = 1; i < 11; i++)
cout << b[i] << " ";
cout << endl;

int m[] = { 0,26,5,77,1,61,11,59,15,48,19 };
int n[11] = { 0 };

MergePass(m, n, 10, 1);
for (int i = 1;i < 11; i++)
cout << n[i] << " ",
cout << endl;

MergePass(m, n, 10, 2);
for (int i = 1; i < 11; i++)
cout << n[i] << " ",
cout << endl;

MergePass(m, n, 10, 4);
for (int i = 1; i < 11; i++)
cout << n[i] << " ",
cout << endl;

MergePass(m, n, 10, 8);
for (int i = 1; i < 11; i++)
cout << n[i] << " ",
cout << endl;
cout << "上面的都是中间结果测试" << endl;

int x[] = { 0,26,5,77,1,61,11,59,15,48,19 };
MergeSort(x, 10);
for (int i = 1; i < 11; i++)
cout << x[i] << " ";
cout << endl;
    return 0;

}

template<class T>
void MergeSort(T *a, const int n)
{
T *tempList = new int[n + 1];
for (int l = 1; l < n; l *=2)
{
MergePass(a, tempList, n, l);
l *=2;
MergePass(tempList, a, n, l);
}
delete[] tempList;
}

template<class T>
void MergePass(T *initList, T *resultList, const int n, const int s)
{
int i;
for (i = 1; i < n - 2 * s + 1; i += 2 * s)//s为数组的长度
Merge(initList, resultList, i, i + s - 1, i + 2 * s - 1);
if ((i + s - 1) < n)
Merge(initList, resultList, i, i + s - 1, n);
else
copy(initList + i, initList + n + 1, resultList + i);
}

template<class T>
void Merge(T *initList, T *mergeList, const int l, const int m, const int n)
{
int i1, i2, iResult;//i1,i2定义两个数组的位置
for (i1 = l, i2 = m + 1, iResult = l; i1 <= m && i2 <= n; iResult++)
{
if (initList[i1] <= initList[i2])
{
mergeList[iResult] = initList[i1];
i1++;
}
else
{
mergeList[iResult] = initList[i2];
i2++;
}

}
//拷贝剩下的
copy(initList + i1, initList + m + 1, mergeList + iResult);
copy(initList + i2, initList + n + 1, mergeList + iResult);
}