## Wednesday, June 7, 2017

### Problem statement

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.
```

### Solution

• We cannot reshape array 2* 2 to 2* 4  matrix. If this is the situation we need to return the array
• We need to declare new matrix array
int [][] reshapedArray= new int [r][c]
• The reshape matrix would be defined using
reshapedArray[i/c][i%c]=nums[i/firstArrayLength][i%firstArrayLength]

```package Algorithms;

public class ReshapeArray {

public static int [][] get(int [][] nums,int r, int c){

int arrayNums=nums.length;
int firstArrayLength=nums.length;

//We cannot reshape an array of 2 * 2 matrix to a 2 * 4 matrix
if(arrayNums*firstArrayLength!=r*c )
return nums;
else
{
//New reshaped array
int [][] reshapedArray= new int [r][c];
for (int i=0;i<r*c;i++)
{
1st iteration
new[0/4][0%4]=nums[0/2][0%2];
new=nums

2nd iteration
new[1/4][1%4]=nums[1/2,1%2]
new    =nums

3rd iteration
new[2/4][2%4]=nums[2/2,2%2]
new = nums[1,0]

4th iteration
[3/4][3%4]=nums[3/2,3%2]
new =nums[1,1]
*/
reshapedArray[i/c][i%c]=nums[i/firstArrayLength][i%firstArrayLength];
}
return reshapedArray;
}

}

}
```