Python实现数字蛇形方阵
输入：数字m mm，n nn
输出：m mm行n nn列的数字蛇形方阵
1. 从方阵最左上角开始，顺时针向内填充。
初始化一个m mm行n nn列的矩阵matrix，所有元素都为0；然后从第一个位置开始，按顺序填充数字，填满了一列或一行后，就转向填写下一列或下一行，最后打印出这个数字蛇形方阵。代码如下：
def print_snake_matrix(m, n): matrix = [[0]*n for i in range(m)] num = 1 i, j = 0, 0 while num <= m*n: while j < n and matrix[i][j] == 0: matrix[i][j] = num num += 1 j += 1 j -= 1 i += 1 while i < m and matrix[i][j] == 0: matrix[i][j] = num num += 1 i += 1 i -= 1 j -= 1 while j >= 0 and matrix[i][j] == 0: matrix[i][j] = num num += 1 j -= 1 j += 1 i -= 1 while i >= 0 and matrix[i][j] == 0: matrix[i][j] = num num += 1 i -= 1 i += 1 j += 1 for row in matrix: for num in row: print(num, end='\t') print()
执行
print_snake_matrix(4, 6)
输出
1 2 3 4 5 6
16 17 18 19 20 7
15 24 23 22 21 8
14 13 12 11 10 9
c++实现
#include <iostream> #include <vector> using namespace std; void print_snake_matrix(int m, int n) { vector<vector<int>> matrix(m, vector<int>(n, 0)); int num = 1; int i = 0, j = 0; while (num <= m * n) { while (j < n && matrix[i][j] == 0) { matrix[i][j] = num; num++; j++; } j--; i++; while (i < m && matrix[i][j] == 0) { matrix[i][j] = num; num++; i++; } i--; j--; while (j >= 0 && matrix[i][j] == 0) { matrix[i][j] = num; num++; j--; } j++; i--; while (i >= 0 && matrix[i][j] == 0) { matrix[i][j] = num; num++; i--; } i++; j++; } for (auto row : matrix) { for (int num : row) { cout << num << "\t"; } cout << endl; } }
2. 从方阵最右上角开始，逆时针向内填充。
由于是从右上角开始填充，所以初始位置为第0 00行第n − 1 n-1n−1列。随后的填充顺序也需要逆时针旋转，以保证填充的数字顺序正确。除此之外，这段代码的实现与前面的代码基本相同，都是采用四个while循环来按顺序填充数字。代码如下：
def print_snake_matrix(m, n): matrix = [[0]*n for i in range(m)] num = 1 i, j = 0, n-1 while num <= m*n: while j >= 0 and matrix[i][j] == 0: matrix[i][j] = num num += 1 j -= 1 j += 1 i += 1 while i < m and matrix[i][j] == 0: matrix[i][j] = num num += 1 i += 1 i -= 1 j += 1 while j < n and matrix[i][j] == 0: matrix[i][j] = num num += 1 j += 1 j -= 1 i -= 1 while i >= 0 and matrix[i][j] == 0: matrix[i][j] = num num += 1 i -= 1 i += 1 j -= 1 for row in matrix: for num in row: print(num, end='\t') print()
执行
print_snake_matrix(4, 6)
输出
6 5 4 3 2 1
7 20 19 18 17 16
8 21 22 23 24 15
9 10 11 12 13 14
c++实现
void print_snake_matrix(int m, int n) { vector<vector<int>> matrix(m, vector<int>(n, 0)); int num = 1; int i = 0, j = n - 1; while (num <= m * n) { while (j >= 0 && matrix[i][j] == 0) { matrix[i][j] = num; num++; j--; } j++; i++; while (i < m && matrix[i][j] == 0) { matrix[i][j] = num; num++; i++; } i--; j++; while (j < n && matrix[i][j] == 0) { matrix[i][j] = num; num++; j++; } j--; i--; while (i >= 0 && matrix[i][j] == 0) { matrix[i][j] = num; num++; i--; } i++; j--; } for (auto row : matrix) { for (int num : row) { cout << num << "\t"; } cout << endl; } }
