基本合并排序中的输出不正确

Question

尝试实现合并排序，但排序输出不正确......

输入：2 8 6 1 10 15 3 12 11 输出为：12 11 15 3 12 11 15 3 8

不确定错误在哪里......

非常感谢任何帮助。感谢

template<class T>
void merge(T data[], int left, int right, T temp[])
{
    int mid = (left+right)/2;
    int l = left, r= mid+1, t=0;

    while(l <= mid && r <= right)
    {
        if(data[l] < data[r])
            temp[t++] = data[l++];
        else
            temp[t++] = data[r++];

    }

    while(l <= mid)
        temp[t++] = data[l++];

    while(r <= right)
        temp[t++] = data[r++];

    //copy it back
    for(int i=0; i<(right-left+1); i++)
        data[i] = temp[i];

}

template<class T>
void merge_helper(T data[], int first, int last, T temp[])
{
    if(first < last)
    {
        int mid = (first+last)/2;
        merge_helper(data, first, mid, temp);
        merge_helper(data, mid+1, last, temp);
        merge(data, first, last, temp);

    }

}


// merge sort

template<class T>
void mergesort(T data[], int size)
{
    T *temp = (T*)malloc(sizeof(T)*size);
    merge_helper(data, 0, size-1, temp);
}

Answer 1

//copy it back
for(int i=0; i<(right-left+1); i++)
 data[i] = temp[i];

当你将它复制回原始数组时，这里可能出现问题，你总是从零开始，你必须将它从左边元素复制回到右边元素。

试试这个

for(int i = left,k=0; i<=right;i++,k++)
data[i] = temp[k];