第一个循环是对矩阵的第一行进行的，第一次循环时除了第一个是1其他都是0，i=0,j=0时H[i + 1, j] =H[1, 0]=0,循环结束时, H[1, 0] =2,i=1,m=3；第二次循环时i=1,j=0，H[i + 1, j] =H[2, 0]=0,循环结束时,H[2, 0] =3,i=2,m=4 ……所以第一个循环相当于把第一行用2到N连续的自然数填充。同样的第二个循环是对最后一列用从N到2N-1的连续自然数进行填充，第三个是对最后一行从右到左用2N-1到3N-2的连续自然数进行填充，第四个是对第一列从下到上用3N-2到4N-3连续自然数进行填充.-The first cycle is carried out the first line of the matrix of the first cycle in addition to the first one is the other one is 0, i = 0, j = 0 when H [i+ 1, j] = H [1, 0] = 0, the end of the cycle, H [1, 0] = 2, i = 1, m = 3　the second time cycle i = 1, j = 0, H [i+ 1, j] = H [2, 0 ] = 0, the end of the cycle, H [2, 0] = 3, i = 2, m = 4　... ... so the first cycle of the first line is equivalent to 2 to use the natural number N consecutive filled. Similarly the second cycle is the final one from N to 2N-1 successive natural numbers to fill, and the third is the last line from right to left with 2N-1 to 3N-2 in a row to fill natural number, the fourth The first column is a bottom-up to the 3N-2 with 4N-3 for the number of filled natural.