《程序员代码面试指南》第八章 数组和矩阵问题 转圈打印矩阵

题目

转圈打印矩阵

java代码

package com.lizhouwei.chapter8;

/**
 * @Description: 转圈打印矩阵
 * @Author: lizhouwei
 * @CreateDate: 2018/4/28 21:52
 * @Modify by:
 * @ModifyDate:
 */
public class Chapter8_1 {

    public void printMatrix(int[][] matrix) {
        int tR = 0;
        int tC = 0;
        int dR = matrix.length - 1;
        int dC = matrix[0].length - 1;
        while (tR < dR) {
            printLToR(matrix, tR++, dR, tC, dC);
            printUToD(matrix, tR, dR, tC, dC--);
            printRToL( matrix,   tR,   dR--,   tC,   dC);
            printDToU( matrix,   tR,   dR,   tC++,   dC);
        }
    }

    private void printLToR(int[][] matrix, int tR, int dR, int tC, int dC) {
        while (tC <= dC) {
            System.out.print(matrix[tR][tC++] + " ");
        }
        System.out.println();

    }

    private void printUToD(int[][] matrix, int tR, int dR, int tC, int dC) {
        while (tR <= dR) {
            System.out.print(matrix[tR++][dC] + " ");
        }
        System.out.println();
    }

    private void printRToL(int[][] matrix, int tR, int dR, int tC, int dC) {
        while (tC <= dC) {
            System.out.print(matrix[dR][dC--] + " ");
        }
        System.out.println();

    }
    private void printDToU(int[][] matrix, int tR, int dR, int tC, int dC) {
        while (tR <= dR) {
            System.out.print(matrix[dR--][tC] + " ");
        }
        System.out.println();
    }

    //测试
    public static void main(String[] args) {
        Chapter8_1 chapter = new Chapter8_1();
        int[][] matrix = {{1, 2, 3, 4, 5}, {14, 15, 16, 17, 6}, {13, 20, 19, 18, 7}, {12, 11, 10, 9, 8}};
        chapter.printMatrix(matrix);
    }
}

结果