Reshape the Matrix

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 two positive integers r and c representing the row number and column number of the wanted reshaped matrix, respectively.

The reshaped matrix need to be filled with all the elements of the original matrix in the same row-traversing order 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.

分析：将给定的数组重新排列，若维数不一致，直接返回原数组

思路：首先判定维数是否一致，若一致，重新赋值即可。

JAVA CODE

class Solution {
    public int[][] matrixReshape(int[][] nums, int r, int c) {
        if(nums.length*nums[0].length!=r*c)
            return nums;
        int[][] mm = new int[r][c];
        int r1 = 0, c1 = 0;
        for(int i = 0; i < nums.length; i++){
            for(int j = 0; j < nums[i].length; j++){
                if(c1==c){
                    r1++;
                    c1 = 0;
                }
                mm[r1][c1++] = nums[i][j];
            }
        }
        return mm;
    }
}