Matrix Similarity After Cyclic Shifts

class Solution {
    public boolean areSimilar(int[][] mat, int k) {
        int m = mat.length, n = mat[0].length;
        // O(m*n)
        for(int i=0; i<m; i++) {
            for(int j=0; j<n; j++) {

                if(mat[i][j]!=mat[i][(j+k)%n])
                    return false;
            }
        }
        return true;
    }
}