我正在尝试深入研究一些算法并坚持使用合并排序。我的意思是它的工作原理，但我正在记录这个算法的步骤，并且它会重复相同的子间隔重复相同的步骤。这是正确的，这是这种算法的工作方式吗？
例如，我有一个数组：
new int[10] { 9, 4, 5, 3, 1, 2, 8, 7, 6, 0 };
这是算法（取自http://www.c-sharpcorner.com/Blogs/14068/merge-sorting-algorithm-in-C-Sharp.aspx）：
static void MergeSort(int[] a, int start, int end)
{
if (start != end)
{
int n = (start + end) / 2;
MergeSort(a, 0, n);
MergeSort(a, n + 1, end);
MainMerge(a, start, (n + 1), end);
}
}
static public void MainMerge(int[] numbers, int left, int mid, int right)
{
t.Add(new Tuple<int, int>(left, right ));
int[] temp = new int[25];
int i, eol, num, pos;
eol = (mid - 1);
pos = left;
num = (right - left + 1);
while ((left <= eol) && (mid <= right))
{
if (numbers[left] <= numbers[mid])
temp[pos++] = numbers[left++];
else
temp[pos++] = numbers[mid++];
}
while (left <= eol)
temp[pos++] = numbers[left++];
while (mid <= right)
temp[pos++] = numbers[mid++];
for (i = 0; i < num; i++)
{
numbers[right] = temp[right];
right--;
}
}
此处t只是一个开端搜索列表。最后，我在t中看到MainMerge函数已多次调用相同的值：
- t Count = 126 System.Collections.Generic.List<System.Tuple<int,int>>
+ [0] {(0, 1)} System.Tuple<int,int>
+ [1] {(0, 1)} System.Tuple<int,int>
+ [2] {(0, 1)} System.Tuple<int,int>
+ [3] {(0, 1)} System.Tuple<int,int>
+ [4] {(0, 1)} System.Tuple<int,int>
+ [5] {(0, 1)} System.Tuple<int,int>
+ [6] {(0, 1)} System.Tuple<int,int>
+ [7] {(0, 1)} System.Tuple<int,int>
+ [8] {(0, 1)} System.Tuple<int,int>
+ [9] {(0, 1)} System.Tuple<int,int>
+ [10] {(0, 1)} System.Tuple<int,int>
+ [11] {(0, 1)} System.Tuple<int,int>
+ [12] {(0, 1)} System.Tuple<int,int>
+ [13] {(0, 1)} System.Tuple<int,int>
+ [14] {(0, 1)} System.Tuple<int,int>
+ [15] {(0, 1)} System.Tuple<int,int>
+ [16] {(0, 1)} System.Tuple<int,int>
+ [17] {(0, 1)} System.Tuple<int,int>
+ [18] {(0, 1)} System.Tuple<int,int>
+ [19] {(0, 1)} System.Tuple<int,int>
+ [20] {(0, 1)} System.Tuple<int,int>
+ [21] {(0, 1)} System.Tuple<int,int>
+ [22] {(0, 1)} System.Tuple<int,int>
+ [23] {(0, 1)} System.Tuple<int,int>
+ [24] {(0, 1)} System.Tuple<int,int>
+ [25] {(0, 1)} System.Tuple<int,int>
+ [26] {(0, 1)} System.Tuple<int,int>
+ [27] {(0, 1)} System.Tuple<int,int>
+ [28] {(0, 1)} System.Tuple<int,int>
+ [29] {(0, 1)} System.Tuple<int,int>
+ [30] {(0, 1)} System.Tuple<int,int>
+ [31] {(0, 1)} System.Tuple<int,int>
+ [32] {(0, 1)} System.Tuple<int,int>
+ [33] {(0, 1)} System.Tuple<int,int>
+ [34] {(0, 1)} System.Tuple<int,int>
+ [35] {(0, 1)} System.Tuple<int,int>
+ [36] {(0, 2)} System.Tuple<int,int>
+ [37] {(0, 2)} System.Tuple<int,int>
+ [38] {(0, 2)} System.Tuple<int,int>
+ [39] {(0, 2)} System.Tuple<int,int>
+ [40] {(0, 2)} System.Tuple<int,int>
+ [41] {(0, 2)} System.Tuple<int,int>
+ [42] {(0, 2)} System.Tuple<int,int>
+ [43] {(0, 2)} System.Tuple<int,int>
+ [44] {(0, 2)} System.Tuple<int,int>
+ [45] {(0, 2)} System.Tuple<int,int>
+ [46] {(0, 2)} System.Tuple<int,int>
+ [47] {(0, 2)} System.Tuple<int,int>
+ [48] {(0, 2)} System.Tuple<int,int>
+ [49] {(0, 2)} System.Tuple<int,int>
+ [50] {(0, 2)} System.Tuple<int,int>
+ [51] {(0, 2)} System.Tuple<int,int>
+ [52] {(0, 2)} System.Tuple<int,int>
+ [53] {(0, 2)} System.Tuple<int,int>
+ [54] {(0, 2)} System.Tuple<int,int>
+ [55] {(0, 2)} System.Tuple<int,int>
+ [56] {(0, 2)} System.Tuple<int,int>
+ [57] {(0, 2)} System.Tuple<int,int>
+ [58] {(0, 2)} System.Tuple<int,int>
+ [59] {(0, 2)} System.Tuple<int,int>
+ [60] {(0, 3)} System.Tuple<int,int>
+ [61] {(0, 3)} System.Tuple<int,int>
+ [62] {(0, 3)} System.Tuple<int,int>
+ [63] {(0, 3)} System.Tuple<int,int>
+ [64] {(0, 3)} System.Tuple<int,int>
+ [65] {(0, 3)} System.Tuple<int,int>
+ [66] {(0, 3)} System.Tuple<int,int>
+ [67] {(0, 3)} System.Tuple<int,int>
+ [68] {(0, 3)} System.Tuple<int,int>
+ [69] {(0, 3)} System.Tuple<int,int>
+ [70] {(0, 3)} System.Tuple<int,int>
+ [71] {(0, 3)} System.Tuple<int,int>
+ [72] {(0, 4)} System.Tuple<int,int>
+ [73] {(0, 4)} System.Tuple<int,int>
+ [74] {(0, 4)} System.Tuple<int,int>
+ [75] {(0, 4)} System.Tuple<int,int>
+ [76] {(0, 4)} System.Tuple<int,int>
+ [77] {(0, 4)} System.Tuple<int,int>
+ [78] {(0, 4)} System.Tuple<int,int>
+ [79] {(0, 5)} System.Tuple<int,int>
+ [80] {(0, 5)} System.Tuple<int,int>
+ [81] {(0, 5)} System.Tuple<int,int>
+ [82] {(0, 5)} System.Tuple<int,int>
+ [83] {(0, 5)} System.Tuple<int,int>
+ [84] {(0, 6)} System.Tuple<int,int>
+ [85] {(0, 6)} System.Tuple<int,int>
+ [86] {(0, 6)} System.Tuple<int,int>
+ [87] {(0, 7)} System.Tuple<int,int>
+ [88] {(0, 7)} System.Tuple<int,int>
+ [89] {(0, 8)} System.Tuple<int,int>
+ [90] {(0, 9)} System.Tuple<int,int>
+ [91] {(2, 3)} System.Tuple<int,int>
+ [92] {(2, 3)} System.Tuple<int,int>
+ [93] {(2, 3)} System.Tuple<int,int>
+ [94] {(2, 3)} System.Tuple<int,int>
+ [95] {(2, 3)} System.Tuple<int,int>
+ [96] {(2, 3)} System.Tuple<int,int>
+ [97] {(2, 3)} System.Tuple<int,int>
+ [98] {(2, 3)} System.Tuple<int,int>
+ [99] {(2, 3)} System.Tuple<int,int>
+ [100] {(2, 3)} System.Tuple<int,int>
+ [101] {(2, 3)} System.Tuple<int,int>
+ [102] {(2, 3)} System.Tuple<int,int>
+ [103] {(3, 4)} System.Tuple<int,int>
+ [104] {(3, 4)} System.Tuple<int,int>
+ [105] {(3, 4)} System.Tuple<int,int>
+ [106] {(3, 4)} System.Tuple<int,int>
+ [107] {(3, 4)} System.Tuple<int,int>
+ [108] {(3, 4)} System.Tuple<int,int>
+ [109] {(3, 4)} System.Tuple<int,int>
+ [110] {(3, 5)} System.Tuple<int,int>
+ [111] {(3, 5)} System.Tuple<int,int>
+ [112] {(3, 5)} System.Tuple<int,int>
+ [113] {(3, 5)} System.Tuple<int,int>
+ [114] {(3, 5)} System.Tuple<int,int>
+ [115] {(4, 6)} System.Tuple<int,int>
+ [116] {(4, 6)} System.Tuple<int,int>
+ [117] {(4, 6)} System.Tuple<int,int>
+ [118] {(4, 7)} System.Tuple<int,int>
+ [119] {(4, 7)} System.Tuple<int,int>
+ [120] {(5, 8)} System.Tuple<int,int>
+ [121] {(5, 9)} System.Tuple<int,int>
+ [122] {(6, 7)} System.Tuple<int,int>
+ [123] {(6, 7)} System.Tuple<int,int>
+ [124] {(7, 8)} System.Tuple<int,int>
+ [125] {(8, 9)} System.Tuple<int,int>
+ Raw View
例如tupple 0-1重复35次！ 35次只是为了排序前2个元素？我在这里错过了什么吗？
答案 0 :(得分：4)
您的实施中存在错误
你在哪里：
static void MergeSort(int[] a, int start, int end)
{
if (start != end)
{
int n = (start + end) / 2;
MergeSort(a, 0, n);
MergeSort(a, n + 1, end);
MainMerge(a, start, (n + 1), end);
}
}
static void MergeSort(int[] a, int start, int end)
{
if (start != end)
{
int n = (start + end) / 2;
MergeSort(a, start, n); // <------------ HERE IS THE FIX
MergeSort(a, n + 1, end);
MainMerge(a, start, (n + 1), end);
}
}
现在你每走一步都会回到整个阵列的开头。