給定一個正整數 n，生成一個包含 1 到 n2 所有元素，且元素按順時針順序螺旋排列的正方形矩陣。

示例:

輸入: 3
輸出:
[
 [ 1, 2, 3 ],
 [ 8, 9, 4 ],
 [ 7, 6, 5 ]
]

C

/**
 * Return an array of arrays.
 * Note: The returned array must be malloced, assume caller calls free().
 */
int** generateMatrix(int n) 
{
    int su=n*n;
    int** res=(int**)malloc(sizeof(int*)*n);
    for(int i=0;i<n;i++)
    {
        res[i]=(int*)malloc(sizeof(int)*n);
    }
    int count=(n+1)/2;
    int k=0;
    int cc=1;
    while(k<count && cc<=su)
    {
        for(int i=k;i<n-k;i++)
        {
            res[k][i]=cc;
            cc++;
        }
        for(int i=k+1;i<n-1-k;i++)
        {
            res[i][n-1-k]=cc;
            cc++;
        }
        if(k!=n-1-k)
        {
            for(int i=k;i<n-k;i++)
            {
                res[n-1-k][n-1-i]=cc;
                cc++;
            }
            for(int i=k+1;i<n-1-k;i++)
            {
                res[n-1-i][k]=cc;
                cc++;
            }
        }
        k++;
    }
    return res;   
}
 

C++

class Solution {
public:
    vector<vector<int>> generateMatrix(int n) 
    {
        int su=n*n;
        vector<vector<int>> res(n);
        for(int i=0;i<n;i++)
        {
            res[i]=vector<int>(n,0);
        }
        int count=(n+1)/2;
        int k=0;
        int cc=1;
        while(k<count && cc<=su)
        {
            for(int i=k;i<n-k;i++)
            {
                res[k][i]=cc;
                cc++;
            }
            for(int i=k+1;i<n-1-k;i++)
            {
                res[i][n-1-k]=cc;
                cc++;
            }
            if(k!=n-1-k)
            {
                for(int i=k;i<n-k;i++)
                {
                    res[n-1-k][n-1-i]=cc;
                    cc++;
                }
                for(int i=k+1;i<n-1-k;i++)
                {
                    res[n-1-i][k]=cc;
                    cc++;
                }
            }
            k++;
        }
        return res;        
    }
};
 

python

class Solution:
    def generateMatrix(self, n):
        """
        :type n: int
        :rtype: List[List[int]]
        """
        su=n**2
        res=[[0 for i in range(n)] for j in range(n)]
        count=(n+1)//2
        cc=1
        k=0
        while k<count and cc<=su:
            for i in range(k,n-k):
                res[k][i]=cc
                cc+=1
            for i in range(k+1,n-1-k):
                res[i][n-1-k]=cc
                cc+=1
            if k!=n-1-k:
                for i in range(k,n-k):
                    res[n-1-k][n-1-i]=cc
                    cc+=1
                for i in range(k+1,n-1-k):
                    res[n-1-i][k]=cc
                    cc+=1
            k+=1
        return res