Question

I have a matrixA like that

[0][1]
[2][3]
[4][5]

And after my custom rotation (different numbering) becomes matrixB like this:

[0][1][2]
[3][4][5]

What i want is to map the numberings of the matrix A to B when i look the matrixA from the left->right.
To explain: matrixA looking from the left->right looks like this.

[1][3][5]
[0][2][4]

And matrixB is as it is

[0][1][2]
[3][4][5]

So i want to map, preferably with an equation these values

1->0
3->1
5->2
0->3
2->4
4->5

The real matrix is much larger so please don’t focus to the size of this matrix

If anyone has any suggestions to find an equation for this mappings or some other way to do the mapping described? i would appreciate it

Answer 1

int height = 2, width = 3;  // of matrix B
int [][] a = {{0,1}, {2, 3}, {4, 5}};
int [][] b = {{0,1,2}, {3,4,5}};
Map<Integer, Integer> map = new HashMap<Integer, Integer>();
for (int i = 0; i < height; ++i) {
    for (int j = 0; j < width; ++j) {
        int b_val = b[i][j];
        int a_val = a[j][height - i - 1];
        map.put(a_val, b_val);
    }
}

Set<Map.Entry<Integer, Integer>> entries = map.entrySet();
Iterator<Map.Entry<Integer, Integer>> it = entries.iterator();
while(it.hasNext()) {
    Map.Entry<Integer, Integer> e = it.next();
    System.out.println(e.getKey() + " -> " + e.getValue());
}

See here in action.