matrixReshape.java

import java.util.*;

public class matrixReshape {
    public static void main(String[] args){

        int array[][]={{1,2},{3,4}};
        int r=1;
        int c=4;
        int new_array[][]=matrixReshape(array,r,c);
        System.out.println(Arrays.deepToString(new_array));
    }

    public static int[][] matrixReshape(int[][] nums, int r, int c) {
        int[][] res = new int[r][c];
        if (nums.length == 0 || r * c != nums.length * nums[0].length)
            return nums;
        int count = 0;
        Queue < Integer > queue = new LinkedList < > ();
        for (int i = 0; i < nums.length; i++) {
            for (int j = 0; j < nums[0].length; j++) {
                queue.add(nums[i][j]);
            }
        }
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < c; j++) {
                res[i][j] = queue.remove();
            }
        }
        return res;
    }
}