867. Transpose Matrix
1. Description
Given a 2D integer array matrix, return the transpose of matrix.
The transpose of a matrix is the matrix flipped over its main diagonal, switching the matrix’s row and column indices.
2. Example
Example 1:
Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [[1,4,7],[2,5,8],[3,6,9]]
Example 2:
Input: matrix = [[1,2,3],[4,5,6]]
Output: [[1,4],[2,5],[3,6]]
3. Constraints
- m == matrix.length
- n == matrix[i].length
- 1 <= m, n <= 1000
- 1 <= m * n <= $10^5$
- $-10^9$ <= matrix[i][j] <= $10^9$
4. Solutions
My Accepted Solution
n = i_matrix.size() * i_matrix.front().size()
Time complexity: O(n)
Space complexity: O(n)
class Solution
{
public:
// vector<vector<int>> transpose(vector<vector<int>>& matrix)
vector<vector<int>> transpose(const vector<vector<int>> &i_matrix)
{
const int rows = i_matrix.size();
const int columns = i_matrix.front().size();
vector<vector<int>> invertedMatrix(columns, vector<int>(rows));
for(int row = 0; row < rows; row++)
{
for(int column = 0; column < columns; column++)
{
invertedMatrix[column][row] = i_matrix[row][column];
}
}
return invertedMatrix;
}
};