Matrix

Question

Hello everyone.

I have been trying to solve this Matrix program wherein if user enters 4, it will generate 16 numbers; if 3, it will generate 9 numbers. I am struggling on the else-if statements. The output must be arranged just like this:
16 15 14 13
9 10 11 12
8 7 6 5
1 2 3 4

This is my current program:

import java.util.Scanner;
public class Matrix {

public static void main(String[] args) {
Scanner mtrx = new Scanner(System.in);
int matrixNum = 4;
int row, col;
int ai = 0, deductor = 0, adder = 1;

System.out.print("Enter matrix to generate (n by n): ");
matrixNum = mtrx.nextInt();

for(row = 1; row <= matrixNum; row++) {
for(col = 1; col <= matrixNum; col++) {
if(col == 1) {
ai = matrixNum*matrixNum - deductor;
}else if((col % 2) == 0) {
ai = matrixNum*col - deductor;
}else {
ai += adder;
}
System.out.print(ai + "\t");
}
System.out.println();
deductor = deductor + matrixNum;
adder +=2;
}
}
}

Answer 1

If something is not clear, ask.

int n = mtrx.nextInt();
int ai = n * n;
for(int row=1; row <= n; row++){
for(int col=1; col <= n; col++){
if(row > 1 && col == 1) ai-=n;
if(row%2 == 0)
System.out.print(++ai +" ");
else
System.out.print(ai-- +" ");
}
System.out.println();
}

Answer 2

After getting the value for n, create a new matrix n x n.
int[][] matrix = new int[n][n];
Then you can loop through the matrix filling it in with an incrementing value, starting from the last row (n-1) and the first column (0). Loop to the end of that row filling in your incrementing value, then step up a row to (n-2) at the last column (n-1) and work towards the first column (0) filling in the values. Then again step up and work forward to the end of the next row etc. Repeat until all the rows are full (row == -1).

Here's some example code;

https://code.sololearn.com/cqppy4AuVVg5/?ref=app

Answer 3

This one doesn't use an array, it just prints the values ...

https://code.sololearn.com/cS0SznbHlWcb/?ref=app

Answer 4

Thank you all so much for helping.