c - 求向量中位数的函数？

Question

我正在尝试编写一个函数来查找给定数组的中位数。我有一个问题，当它开始时它没有为偶数或奇数输出正确的值。然而，排序的输入工作。有人看到我的代码有什么问题吗？谢谢！

double vect_median( const double x[], unsigned length)
{
    double ordered[LENGTH] = {0}; //new vector to hold the ordered items, use of {} to accommodate larger sizes
    int temp = 0; //var to hold the value of an item for re-arrangement
    float result = 0;

    for (size_t k = 0; k < length; ++k)
    {
        ordered[k] = x[k];
    }


    for (size_t i = 1; i < length; ++i) //loops to order the values of the vector, start at 1 because length != 0
    {
        for (size_t n = 0; n < (length - 1); ++n) //loop to indivudally check each value
        {
            if (ordered[n] > ordered[n + 1]) //if first is greater than second
            {
                temp = ordered[n];  //switch the order of the two values
                ordered[i] = ordered[i + 1];
                ordered[i+1] = temp;

            }
        }

        //once a value is switched, the loops breaks and the outside loop runs it again LENGTH times
        if(length % 2 == 1)//if odd
        {
            result = ordered[LENGTH/2]; //return the val in the middle of the dataset
        }
        else
        {
            result = (ordered[LENGTH/2] + ordered[LENGTH/2 - 1])/2;

        }
    }  
      return(result);
}

标签： cmedian

Answer 1

这是错误的，因为它i在根据以下内容做出决定后使用n：

        if (ordered[n] > ordered[n + 1]) //if first is greater than second
            {
                temp = ordered[n];  //switch the order of the two values
                ordered[i] = ordered[i + 1];
                ordered[i+1] = temp;

            }