Chapter5_Arrays_Ex13

/*
    =====================================================
                   chapter 5: Arrays

      Ex13: snake matrix
    =====================================================
*/

public class MyProgram {
    public static void main(String[] args) {

        //variables

        // define the range of random number
        final int MAX = 8;
        final int MIN = 4;
        int range = MAX - MIN + 1;

        int ROW=(int)(Math.random()*range)+MIN;   //row's range[4,8]
        int COL=(int)(Math.random()*range)+MIN;  //col's range[4,8]

        int matrix[][]=new int[ROW][COL];
        int number=1;
        boolean toggle=true;    //toggle regardless col even or odd

        System.out.println("row="+ROW+" col="+COL);

        //init snake matrix
        for (int col = COL - 1; col >= 0; col--) {
            if (toggle) {
                for (int row = 0; row < ROW; row++) {   //start the snake at the top right
                    matrix[row][col] = number;
                    number++;
                    toggle=false;
                }
            } else {
                for (int row = ROW - 1; row >= 0; row--) {
                    matrix[row][col] = number;
                    number++;
                    toggle=true;
                }
            }
        }

        //display snake matrix
        for(int row=0;row<ROW;row++) {
            for (int col = 0; col < COL; col++){
                System.out.print(matrix[row][col]);
                System.out.print("\t\t\t");
            }
            System.out.println();
        }
    }
}