Method swap

48-rotate-image/48-rotate-image.java:2–9

(int[][] matrix)

class Solution {
    public void swap(int[][] matrix){
        int rows = matrix.length;
        for(int i=0;i<rows/2;i++){
            int[] temp = matrix[i];
            matrix[i] = matrix[rows-1-i];
            matrix[rows-1-i] = temp;
        }
    }
    public void rotate(int[][] matrix) {
        int n = matrix.length;
        swap(matrix);