LeetCode: Spiral Matrix
Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
For example, Given the following matrix:
You should return
境界に注意する.
For example, Given the following matrix:
[
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ]
]
You should return
[1,2,3,6,9,8,7,4,5] . 境界に注意する.
class Solution {
public:
vector<int> spiralOrder(vector<vector<int> > &matrix) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<int> result;
int m = matrix.size();
if (m == 0) return result;
int n = matrix[0].size();
if (n == 0) return result;
int min = (m < n ? m : n);
int layer = min / 2;
for (int i = 0; i < layer; ++i)
{
for (int j = i; j < n-1-i; ++j)
{
result.push_back(matrix[i][j]);
}
for (int j = i; j < m-1-i; ++j)
{
result.push_back(matrix[j][n-1-i]);
}
for (int j = n-1-i; j > i; --j)
{
result.push_back(matrix[m-1-i][j]);
}
for (int j = m-1-i; j > i; --j)
{
result.push_back(matrix[j][i]);
}
}
if (min % 2 == 1)
{
if (m > n)
{
for (int i = layer; i <= m-1-layer; ++i)
result.push_back(matrix[i][n/2]);
}
else
{
for (int i = layer; i <= n-1-layer; ++i)
result.push_back(matrix[m/2][i]);
}
}
}
};