题目
将正方形矩阵顺时针转动90
java代码
package com.lizhouwei.chapter8;
/**
* @Description: 将正方形矩阵顺时针转动90
* @Author: lizhouwei
* @CreateDate: 2018/4/28 22:16
* @Modify by:
* @ModifyDate:
*/
public class Chapter8_2 {
public void rotate(int[][] matrix) {
int tR = 0;
int tC = 0;
int dR = matrix.length - 1;
int dC = matrix[0].length - 1;
while (tR < dR) {
rotateEdge(matrix, tR++, dR--, tC++, dC--);
}
}
public void rotateEdge(int[][] matrix, int tR, int dR, int tC, int dC) {
int times = dC - tC;
int temp = 0;
for (int i = 0; i < times; i++) {
temp = matrix[tR][tC + i];
matrix[tR][tC + i] = matrix[dR - i][tC];
matrix[dR - i][tC] = matrix[dR][dC - i];
matrix[dR][dC - i] = matrix[tR + i][dC];
matrix[tR + i][dC] = temp;
}
}
//测试
public static void main(String[] args) {
Chapter8_2 chapter = new Chapter8_2();
int[][] matrix = {{1, 2, 3, 4}, {5,6,7,8}, {9, 10, 11, 12}, {13, 14, 15, 16 }};
chapter.rotate(matrix);
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix[0].length; j++) {
System.out.print(matrix[i][j]+" ");
}
System.out.println( );
}
}
}
结果
![](https://images2018.cnblogs.com/blog/1369004/201804/1369004-20180428223715120-1776134220.png)