LeetCode:59. Spiral Matrix II 螺旋矩阵 II（C语言）-蒲公英云

LeetCode:59. Spiral Matrix II 螺旋矩阵 II（C语言）

题目描述：
给定一个正整数 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正方形矩阵。

示例:

输入: 3
输出:
[
[ 1, 2, 3 ],
[ 8, 9, 4 ],
[ 7, 6, 5 ]
]

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/spiral-matrix-ii
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。
解答：

/** * 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)
{ 
    *returnSize = n;//返回行数
    int **ret = (int**)malloc(sizeof(int*)*n);
    int i = 0;
    int j = 0;
    int count = 1;
    int left = 0;
    int right = n-1;
    int top = 0;
    int down = n-1;
    for(i = 0;i<n;i++)
    { 
        ret[i] = (int*)malloc(sizeof(int)*n);
    }
    while(left < right)
    { 
        for(j = left;j<=right;j++)
        { 
            ret[top][j] = count;
            count++;
        }
        top++; 
        for(i = top;i<=down;i++)
        { 
            ret[i][right] = count;
            count++;
        }
        right--; 
        for(j = right;j>=left;j--)
        { 
            ret[down][j] = count;
            count++;
        }
        down--;
        for(i = down;i>=top;i--)
        { 
            ret[i][left] = count;
            count++;
        }
        left++;
    }
    if(left == right)
    { 
        ret[top][left] = count;
    }
    *returnColumnSizes = malloc(sizeof(void*)*n);
    for(i = 0;i<n;i++)
    { 
        (*returnColumnSizes)[i] = n;//返回的每行的长度
    }
    return ret;
}