> Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.
For example, Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ]
解题思路：
跟 一样。
vector<vector<int> > generateMatrix(int n)
{
if(n == 0) return vector<vector<int> >();
vector<vector<int> > matrix(n, vector<int>(n, 0));
int rowindex = 0;
int columeindex = n-1;
int row = n, colume = n;
int index = 1;
int size = n * n;
while(true)
{
int toleft_start = rowindex;
int toleft_end = columeindex;
int todown_start = rowindex + 1;
int todown_end = row - rowindex - 1;
for(int i = toleft_start; i <= toleft_end; i++)
matrix[rowindex][i] = index++;
if(index == size+1)
break;
for(int i = todown_start; i <= todown_end; i++)
matrix[i][columeindex] = index++;
if(index == size+1)
break;
for(int i = toleft_end-1; i>= toleft_start; i--)
matrix[row - rowindex - 1][i] = index++;
if(index == size+1)
break;
for(int i = todown_end-1; i >= todown_start; i--)
matrix[i][colume-columeindex-1] = index++;
if(index == size+1)
break;
rowindex++;
columeindex--;
}
return move(matrix);
}