4_Types_Of_Matrices

package demo;

public class HelloJava {
    public static void main(String[] args) {
        int N = 4;

        int[][] arr = new int[N][N];
        int counter = 1;

        // Columns matrix
        for(int col = 0; col < arr.length; col++){
            for(int row = 0; row < arr[col].length; row++){
                arr[row][col] = counter;
                counter++;
            }
        }

        printMatrix(arr);

        System.out.println();

        // Alternating columns matrix
        counter = 1;
        for(int col = 0; col < arr.length; col++){
            if(col % 2 == 0){
                for(int row = 0; row < arr[col].length; row++){
                    arr[row][col] = counter;
                    counter++;
                }
            }else{
                for(int row = arr[col].length - 1; row >= 0; row--){
                    arr[row][col] = counter;
                    counter++;
                }
            }
        }

        printMatrix(arr);

        System.out.println();

        // Diagonal matrix
        counter = 1;
        int row = N - 1;
        int col = 0;

        while(counter <= (N * N)){
            arr[row][col] = counter;
            counter++;

            if(row == N - 1 && col != N - 1){
                row = N - 2 - col;
                col = 0;
            }else if(col == N - 1){
                col = col - row + 1;
                row = 0;
            }else{
                row++;
                col++;
            }
        }

        printMatrix(arr);

        System.out.println();

        for(int i = 0; i < arr.length; i++){
            for(int j = 0; j < arr[i].length; j++){
                arr[i][j] = 0;
            }
        }

        // Spiral matrix
        counter = 1;
        row = 0;
        col = 0;
        String direction = "down";

        while(counter <= (N * N)){
            arr[row][col] = counter;
            counter++;

            if(direction == "down"){
                row++;

                if(arr[row][col] != 0){
                    direction = "right";
                    row--;
                    col++;
                }else if(row == (N - 1)){
                    direction = "right";
                }

            }else if(direction == "right"){
                col++;
                if(arr[row][col] != 0){
                    direction = "up";
                    col--;
                    row--;
                }else if(col == (N - 1)){
                    direction = "up";
                }

            }else if(direction == "up"){
                row--;

                if(arr[row][col] != 0){
                    direction = "left";
                    row++;
                    col--;
                }else if(row == 0){
                    direction = "left";
                }

            }else if(direction == "left"){
                col--;
                if(col == (N - 1)){
                    direction = "down";
                }else if(arr[row][col] != 0){
                    direction = "down";
                    col++;
                    row++;
                }

            }
        }

        printMatrix(arr);

        System.out.println();


    }

    public static void printMatrix(int[][] arr){
        int spaces = Integer.toString(arr.length * arr.length).length();

        for(int i = 0; i < arr.length; i++){
            for(int j = 0; j < arr[i].length; j++){
                System.out.print(padSpace(arr[i][j], spaces));
                System.out.print((j != arr[i].length - 1) ? " " : "");
            }
            System.out.println();
        }
    }

    public static String padSpace(int num, int spaces){
        String result = String.valueOf(num);
        int difference = spaces - result.length();

        if(difference > 0){
            for(int i = 0; i < difference; i++){
                result = " " + result;
            }
        }
        return result;
    }
}