1. 题目描述
给你一个正整数 n ,生成一个包含 1 到 n2 所有元素,且元素按顺时针顺序螺旋排列的 n x n 正方形矩阵 matrix 。
示例 1:
输入:n = 3
输出:[[1,2,3],[8,9,4],[7,6,5]]
示例 2:
输入:n = 1
输出:[[1]]
提示:
1 <= n <= 20
通过次数63,103提交次数80,422
2.代码如下
/**
* Return an array of arrays of size *returnSize.
* The sizes of the arrays are returned as *returnColumnSizes array.
* Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().
*/
int** generateMatrix(int n, int* returnSize, int** returnColumnSizes){
int i = 0;
int up = 0,down = n-1,left = 0,right = n-1;
int cur_num = 1;
int *colsize = (int *)malloc(sizeof(int)*n);
int **res = (int **)malloc(sizeof(int *)*n);
for (i = 0; i < n;i++)
{
res[i] = (int *)malloc(sizeof(int)*n);
colsize[i] = n;
}
*returnSize = n;
*returnColumnSizes = colsize;
while (1)
{
for (i = left; i <= right;i++)
{
res[up][i] = cur_num;
cur_num += 1;
}
up +=1;
if (up > down)
{
break;
}
for (i = up;i <= down;i++)
{
res[i][right] = cur_num;
cur_num +=1;
}
right -=1;
if (left > right)
{
break;
}
for (i = right;i >= left;i--)
{
res[down][i] = cur_num;
cur_num += 1;
}
down -= 1;
if (up > down)
{
break;
}
for (i = down;i >= up;i--)
{
res[i][left] = cur_num;
cur_num += 1;
}
left += 1;
if (left > right)
{
break;
}
}
return res;
}