Question

如何编写一个方法来创建一个填充的nxn矩阵，如下所示：

int[,] Matrix(int n) or int[][] Matrix(int n) for example for n = 5:

1 2 3 4 5
16 17 18 19 6
15 24 25 20 7
14 23 22 21 8
13 12 11 10 9

Answer 1

一个解决方案就是：

static int[,] Matrix(int n)
{
    if (n < 0)
        throw new ArgumentException("n must be a positive integer.", "n");

    var result = new int[n, n];                    

    int level = 0,
        counter = 1;
    while (level < (int)Math.Ceiling(n / 2f))
    {
        // Start at top left of this level.
        int x = level, 
            y = level;
        // Move from left to right.
        for (; x < n - level; x++)           
            result[y, x] = counter++;            
        // Move from top to bottom.
        for (y++, x--; y < n - level; y++)            
            result[y, x] = counter++;            
        // Move from right to left.
        for (x--, y--; x >= level; x--)            
            result[y, x] = counter++;            
        // Move from bottom to top. Do not overwrite top left cell.
        for (y--, x++; y >= level + 1; y--)            
            result[y, x] = counter++;            
        // Go to inner level.
        level++;
    }

    return result;
}

以下是打印到控制台的结果矩阵（介于1和6之间）：

Result

Answer 2

这可以在MSDN Example中实现。

Google Search Results

// Two-dimensional array. 
int[,] array2D = new int[,] { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 } };
// The same array with dimensions specified. 
int[,] array2Da = new int[4, 2] { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 } };
// A similar array with string elements. 
string[,] array2Db = new string[3, 2] { { "one", "two" }, { "three", "four" },
                                        { "five", "six" } };

// Three-dimensional array. 
int[, ,] array3D = new int[,,] { { { 1, 2, 3 }, { 4, 5, 6 } }, 
                                 { { 7, 8, 9 }, { 10, 11, 12 } } };
// The same array with dimensions specified. 
int[, ,] array3Da = new int[2, 2, 3] { { { 1, 2, 3 }, { 4, 5, 6 } }, 
                                       { { 7, 8, 9 }, { 10, 11, 12 } } };

// Accessing array elements.
System.Console.WriteLine(array2D[0, 0]);
System.Console.WriteLine(array2D[0, 1]);
System.Console.WriteLine(array2D[1, 0]);
System.Console.WriteLine(array2D[1, 1]);
System.Console.WriteLine(array2D[3, 0]);
System.Console.WriteLine(array2Db[1, 0]);
System.Console.WriteLine(array3Da[1, 0, 1]);
System.Console.WriteLine(array3D[1, 1, 2]);

// Getting the total count of elements or the length of a given dimension. 
var allLength = array3D.Length;
var total = 1;
for (int i = 0; i < array3D.Rank; i++) {
    total *= array3D.GetLength(i);
}
System.Console.WriteLine("{0} equals {1}", allLength, total);

// Output: 
// 1 
// 2 
// 3 
// 4 
// 7 
// three 
// 8 
// 12 
// 12 equals 12

C＃创建NxN矩阵的方法

2 个答案: