Rotate Image
问题描述：
You are given an n x n 2D matrix representing an image.
Rotate the image by 90 degrees (clockwise).
Follow up: Could you do this in-place?
测试代码：
class Solution {
public:
void rotate(
vector<vector<int>>& matrix) {
int size = matrix.size();
int temp = -
1;
vector<vector<int>> result(size,
vector<int>(size,-
1));
for(
int i=
0;i<size;i++)
{
for(
int j=
0;j<size;j++)
{
result[j][size-i-
1] = matrix[i][j];
}
}
matrix = result;
}
};
性能：
参考答案：
class Solution {
public:
void rotate(
vector<vector<int>>& matrix) {
int n = matrix.size();
for (
int i =
0; i < n -
1; ++i) {
for (
int j =
0; j < n - i -
1; ++j) {
swap(matrix[i][j], matrix[n -
1 - j][n -
1 - i]);
}
}
reverse(matrix.begin(), matrix.end());
}
};
性能：
