In MATLAB, there is a very useful function called 'reshape', which can reshape a matrix into a new one with different size but keep its original data.

You're given a matrix represented by a two-dimensional array, and twopositiveintegersrandcrepresenting therownumber andcolumnnumber of the wanted reshaped matrix, respectively.

The reshaped matrix need to be filled with all the elements of the original matrix in the samerow-traversingorder as they were.

If the 'reshape' operation with given parameters is possible and legal, output the new reshaped matrix; Otherwise, output the original matrix.

Example 1:

Input: 
nums = 
[[1,2],
 [3,4]]
r = 1, c = 4
Output: 
[[1,2,3,4]]
Explanation:
 
The row-traversing of nums is [1,2,3,4]. The new reshaped matrix is a 1 * 4 matrix, fill it row by row by using the previous list.

Example 2:

Input: 
nums = 
[[1,2],
 [3,4]]
r = 2, c = 4
Output: 
[[1,2],
 [3,4]]
Explanation:
There is no way to reshape a 2 * 2 matrix to a 2 * 4 matrix. So output the original matrix.

Note:

1. The height and width of the given matrix is in range [1, 100].
2. The given r and c are all positive.

class Solution {
    public int[][] matrixReshape(int[][] nums, int r, int c) {
        int m = nums.length, n = nums[0].length;
        if(r * c != m * n) return nums;
        int[] num = new int[m*n];
        for(int i = 0; i < m; i++) {
            for(int j = 0; j < n; j++)
                num[i * n + j] = nums[i][j];
        }
        int[][] res = new int[r][c];
        for(int i = 0; i < r; i++) {
            for(int j = 0; j < c; j++) {
                res[i][j] = num[i * c + j];
            }
        }
        return res;
    }
}