Cyclically Rotating a Grid.java

class Solution {
    public int[][] rotateGrid(int[][] grid, int k) {
        int m = grid.length, n = grid[0].length, noOfLayers = Math.min(m/2, n/2); 
        // Peeling each layer one by one
        for(int layerNo = 0; layerNo < noOfLayers; layerNo++){
            // Please suggest if you have better way to find perimeter of matrix on a given layer!
            int perimeter = (m-(2*layerNo)) + (n-(2*layerNo)-1) + (m-(2*layerNo)-1) + (n-(2*layerNo)-2); 
            int[] layer = new int[perimeter]; // this out be use to store that particular layer
            readLayer(grid, layer, layerNo, m, n); // this will read the layer
            writeLayer(grid, layer, layerNo, m, n, k); // this will rotate it by k and write back the layer  
        }
        return grid;
    }
    
    public void readLayer(int[][] grid, int[] layer, int layerNo, int m, int n){
        int count = 0, r = layerNo, c = layerNo;
        m--; n--;
        // read left a -> c
        for(int i = layerNo; i < n - layerNo; i++) layer[count++] = grid[layerNo][i];
        // read down c -> i
        for(int i = layerNo; i < m - layerNo; i++) layer[count++] = grid[i][n-layerNo];
        // read right i -> g
        for(int i = n-layerNo; i > layerNo; i--) layer[count++] = grid[m-layerNo][i];
        // read up g -> a
        for(int i = m-layerNo; i > layerNo; i--) layer[count++] = grid[i][layerNo];
    }
    
    public void writeLayer(int[][] grid, int[] layer, int layerNo, int m, int n, int k){
         m--; n--;
        int len = layer.length, count = k; 
        // write left a -> c
        for(int i = layerNo; i < n - layerNo; i++){
            count %= len; // reason if goes out of length start back from 0
            grid[layerNo][i] = layer[count++];
        }
        // write down c -> i
        for(int i = layerNo; i < m - layerNo; i++){
            count %= len;
            grid[i][n-layerNo] = layer[count++];
        } 
        // write right i -> g
        for(int i = n-layerNo; i > layerNo; i--){
            count %= len;
            grid[m-layerNo][i] = layer[count++];
        }
        // write up g -> a
        for(int i = m-layerNo; i > layerNo; i--){
            count %= len;
            grid[i][layerNo] = layer[count++];
        } 
    }
    
   
}