566. 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.
Note:
The height and width of the given matrix is in range [1, 100].
The given r and c are all positive.
题意：重塑数组。给定一个数组，若能重塑成r行c列的，就返回重塑的数组，否则返回原数组。重塑原则是按照行优先进行。思路：如果r*c!=r1*c1，肯定不能重塑，则返回原数组。否则用一个一维数组按照行的顺序将原始的二维数组保存起来，再分配给新的二维数组。代码：class Solution {
public int[][] matrixReshape(int[][] nums, int r, int c) {
int r1=nums.length;
int c1=nums[0].length;
int [][]arr=new int[r][c];
int []t=new int[r1*c1];
if(r1*c1!=r*c)
return nums;
else
{
int ans=0;
for(int i=0;i<r1;i++)
{
for(int j=0;j<c1;j++)
{
t[ans++]=nums[i][j];
}
}
int h=0;
for(int i=0;i<r;i++)
{
for(int j=0;j<c;j++)
{
arr[i][j]=t[h++];
}
}
return arr;
}
}
}