快速排序 and 拉格朗日插值查找

Posted 2021-01-20 zhaodadan

        private static void QuictSort(int[] zu, int left, int right)
        {
            if (left < right)
            {
                int i = 0;
                int j = right - 1;
                int mid = zu[(left + right) / 2];
                while (true)
                {
                    while (i<right && zu[i]<mid)
                    {
                        i++;                        
                    }
                    while (j > left && zu[j] > mid)
                    {
                        j--;                       
                    }
                    if (i == j)
                    {
                        break;
                    }
                    int temp = zu[i];
                    zu[i] = zu[j];
                    zu[j] = temp;
                    if (zu[i] == zu[j])
                    {
                        j--;
                    }
                }
                QuictSort(zu, left, i);
                QuictSort(zu, i + 1, right);
            }
            
        }

// 拉格朗日插值查找

 private static int LChaZhao(int[] zu, int key)
        {
            int left = 0;
            int right = zu.Length - 1;
            int middle = -1;
            while (left <= right)
            {
                middle = left + (right - left) * (key - zu[left]) / (zu[right] - zu[left]);
                if (key == zu[middle])
                {
                    return middle;
                }
                else if (key > zu[middle])
                {
                    left = middle + 1;
                }
                else
                {
                    right = middle - 1;
                }
            }
            return -1;
        }