leetcode566. Reshape the Matrix

https://leetcode.com/problems/reshape-the-matrix/description/

public int[][] matrixReshape(int[][] nums, int r, int c) {
    int m = nums.length, n = nums[].length;
    if (r * c != m * n)
        return nums;
    int[][] reshaped = new int[r][c];
    for (int i = ; i < r * c; i++)
        reshaped[i/c][i%c] = nums[i/n][i%n];    %核心公式
    return reshaped;
}

序号对行数整除，取整是所在行数。对行数求余，是所在列数。

自己的代码：1.不够简洁 ，有点累赘 2.compiler error,找不出原因，哈哈哈哈

class Solution {
public:
    vector<vector<int>> matrixReshape(vector<vector<int>>& nums, int r, int c) {
         vector<vector<int>>  nums1(r,vector<int>(c));
        if((nums.size()*nums[].size())==r*c)
        {

             for(int i=;i<r;i++)
            {
                for(int j=;j<c;j++)
                {
                    cout<<nums[i][j]<<" ";
                    nums1[i][j]=nums[i][j];

                }
               cout<<"\n";
             }

        }
        else
        {
            cout<<"the shape no match!"<<endl;
            for(int i=;i<nums.size();i++)
            {
                for(int j=;j<nums[i].size();j++)
                {
                    cout<<nums[i][j]<<" ";
                    nums1[i][j]=nums[i][j];

                }
               cout<<"\n";
            }

    }

        return nums1;
}};