归并排序

归并排序的数组实现

//折半插入排序
void insertSort_Binary(int *arr, int len)
{
    int i, j;//工作指针
    int low, mid, high;//折半查找指针
    int current;//暂存待插入的元素

    //将各个元素插入到前面的有序序列
    for(i = 0; i< len; i++)
    {
        current = arr[i];
        low = 0;
        high = i - 1;
        while(low <= high)
        {
            mid = low + (high-low)/2;
            if(arr[mid] > current)
                high = mid - 1;
            else
                low = mid + 1;
        }
        //后移元素
        for(j = i - 1; j >= high+1; j--)
            arr[j+1] = arr[j];
        //插入目标元素
        arr[high+1] = current;
    }
}

//归并排序
void mergeSort(int *arr, int len1, int *arr2, int len2, int *arr3)
{
    int i = 0;//遍历数组1的指针
    int j = 0;//遍历数组2的指针
    int k = 0;//存储归并后的元素的指针

    //对数组1、2进行排序，使之成为有序数组
    insertSort_Binary(arr1,len1);
    insertSort_Binary(arr2,len2);

    while(i < len1 && i < len2)
    {
        if(arr1[i] < arr2[j])
            arr3[k++] = arr1[i++]；
        else
            arr3[k++] = arr2[j++];
    }
    while(i < len1)
        arr3[k++] = arr1[i++];
    while(j < len2)
        arr3[k++] = arr2[j++];
}