find duplicates in matrix within k indices

import java.util.*;public class find_dupicates_within_k_indices {    static class Pos {        int row;        int col;        Pos(int row, int col) {            this.row = row;            this.col = col;        }        public int getRow() {            return row;        }        public int getCol() {            return col;        }        public boolean equals(Object o) {            Pos p = (Pos) o;            if (p == null) return false;            return p.row == row && p.col == col;        }        public int hashCode() {            return this.row + this.col;        }    }    public static void findDupicates(int[][] matrix, int k) {        Map < Integer, Set < Pos >> store = new HashMap < Integer, Set < Pos >> ();        for (int row = 0; row < matrix.length; row++) {            for (int col = 0; col < matrix[0].length; col++) {                int val = matrix[row][col];                if (store.containsKey(val)) {                    Set < Pos > set = store.get(val);                    for (Pos p: set) {                        if (Math.abs(p.getRow() - row) + Math.abs(p.getCol() - col) <= k) {                            System.out.println("YES");                            return;                        }                        if (row - p.getRow() > k) set.remove(p);                    }                    set.add(new Pos(row, col));                } else {                    Set < Pos > set = new HashSet < Pos > ();                    set.add(new Pos(row, col));                    store.put(val, set);                }            }        }        System.out.println("NO");        return;    }    public static void main(String[] args) {        // TODO Auto-generated method stub        // int[][] matrix1 = {{1,2,3}, {4, 5, 6}, {7,8,9}, {10, 11, 12}};        // int[][] matrix2 = {{1,2,3}, {3, 5, 6}, {7,8,9}, {10, 11, 12}};        //        // int k = 3;        // findDupicates(matrix1, k);        // findDupicates(matrix2, k);        Scanner in = new Scanner(System. in );        String tmp1;        String tmp2;        tmp1 = in .nextLine();        tmp2 = in .nextLine();        int row = Integer.parseInt(tmp1);        String[] tmpNum = tmp2.split(" ");        int col = tmpNum.length;        int[] row1 = new int[col];        for (int i = 0; i < col; i++) {            row1[i] = Integer.parseInt(tmpNum[i]);        }        int[][] matrix = new int[row][col];        matrix[0] = row1;        for (int i = 1; i < row; i++) {            String[] tmpStr = in .nextLine().split(" ");            for (int j = 0; j < col; j++) {                matrix[i][j] = Integer.parseInt(tmpStr[j]);            }        }        int k = in .nextInt();        // if(in.hasNextInt()) {        // System.out.println("ERROR");        // return;        // }        findDupicates(matrix, k);    }}