Sorted matrix.cpp

/*
Sorted matrix
=============

Given an NxN matrix Mat. Sort all elements of the matrix.

Example 1:
Input:
N=4
Mat=[[10,20,30,40],
[15,25,35,45] 
[27,29,37,48] 
[32,33,39,50]]
Output:
10 15 20 25 
27 29 30 32
33 35 37 39
40 45 48 50
Explanation:
Sorting the matrix gives this result.

Example 2:
Input:
N=3
Mat=[[1,5,3],[2,8,7],[4,6,9]]
Output:
1 2 3 
4 5 6
7 8 9
Explanation:
Sorting the matrix gives this result.
Your Task:
You don't need to read input or print anything. Your task is to complete the function sortedMatrix() which takes the integer N and the matrix Mat as input parameters and returns the sorted matrix.

Expected Time Complexity:O(N2LogN)
Expected Auxillary Space:O(N2)

Constraints:
1<=N<=1000
1<=Mat[i][j]<=105
*/

vector<vector<int>> sortedMatrix(int N, vector<vector<int>> Mat)
{
  vector<int> sorted;
  for (auto &row : Mat)
  {
    for (auto &i : row)
      sorted.push_back(i);
  }
  sort(sorted.begin(), sorted.end());
  int i = 0;
  for (auto &row : Mat)
  {
    for (auto &e : row)
    {
      e = sorted[i];
      i++;
    }
  }
  return Mat;
}