Solving Rotate Image in go. Please try yourself first to solve the problem and submit your implementation to LeetCode before looking into solution.

## Problem Description

Rotate the image by 90 degrees (clockwise).

Note:

Example 1:

``````Given input matrix =
[
[1,2,3],
[4,5,6],
[7,8,9]
],

rotate the input matrix in-place such that it becomes:
[
[7,4,1],
[8,5,2],
[9,6,3]
]``````

Example 2:

``````Given input matrix =
[
[ 5, 1, 9,11],
[ 2, 4, 8,10],
[13, 3, 6, 7],
[15,14,12,16]
],

rotate the input matrix in-place such that it becomes:
[
[15,13, 2, 5],
[14, 3, 4, 1],
[12, 6, 8, 9],
[16, 7,10,11]
]``````
``````    /*
* first reverse up to down, then swap the symmetry
* 1 2 3     7 8 9     7 4 1
* 4 5 6  => 4 5 6  => 8 5 2
* 7 8 9     1 2 3     9 6 3
*/
void rotate(vector<vector<int> > &matrix) {
reverse(matrix.begin(), matrix.end());
for (int i = 0; i < matrix.size(); ++i) {
for (int j = i + 1; j < matrix[i].size(); ++j)
swap(matrix[i][j], matrix[j][i]);
}
}

/*
* first reverse left to right, then swap the symmetry
* 1 2 3     3 2 1     3 6 9
* 4 5 6  => 6 5 4  => 2 5 8
* 7 8 9     9 8 7     1 4 7
*/
void anti_rotate(vector<vector<int> > &matrix) {
for (auto vi : matrix) reverse(vi.begin(), vi.end());
for (int i = 0; i < matrix.size(); ++i) {
for (int j = i + 1; j < matrix[i].size(); ++j)
swap(matrix[i][j], matrix[j][i]);
}
}``````

See the full details of the problem Rotate Image at LeetCode

Originally posted at: @github.com/halfrost/LeetCode-Go