Problem
Print a matrix in spiral fashion.
Solution
We will first print the periphery of the matrix by the help of 4 for loops. Then recursively call this function to do the same thing with inner concentric rectangles. We will pass this information by a variable named depth, which will tell how many layers from outside should be ignored.
Code
public class PrintMatrixSpiral { public static void main(String[] args) { int[][] matrix = { { 3, 4, 5, 6, 2, 5 }, { 2, 4, 6, 2, 5, 7 }, { 2, 5, 7, 8, 9, 3 }, { 2, 4, 7, 3, 5, 8 }, { 6, 4, 7, 3, 5, 7 } }; printSpiral(matrix); } public static void printSpiral(int[][] matrix) { printSpiral(matrix, 0); } private static void printSpiral(int[][] matrix, int depth) { if (matrix == null && matrix.length == 0) return; int rows = matrix.length; int cols = matrix[0].length; if (2 * depth > Math.min(rows, cols)) return; for (int i = depth; i < cols - depth - 1; ++i) { System.out.print(matrix[depth][i] + ","); } for (int i = depth; i < rows - depth - 1; ++i) { System.out.print(matrix[i][cols - depth - 1] + ","); } for (int i = rows - depth; i > depth; --i) { System.out.print(matrix[rows - depth - 1][i] + ","); } for (int i = rows - depth - 1; i > depth; --i) { System.out.print(matrix[i][depth] + ","); } printSpiral(matrix, ++depth); } }
时间: 2024-11-05 23:22:03