[LeetCode] Spiral Matrix II

Spiral Matrix II

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：

http://blog.csdn.net/kangrydotnet/article/details/44727955的姐妹篇。不停的进行扫描而已。注重分析能力。

源代码：

class Solution {
public:
    vector<vector<int> > generateMatrix(int n) {
        int** d=new int*[n];
        for(int i=0; i<n; i++){
            d[i] = new int[n];
        }

        int x=0, y=0;
        int data=1;
        while(data<=n*n){
            //赋值上边
            for(int i=y; i < n-y; i++){
                d[x][i] = data;
                data++;
            }
            
            //赋值右边
            for(int i=x+1; i< n-x; i++){
                d[i][n-y-1]=data;
                data++;
            }
            
            //赋值下边
            for(int i=n-y-2; i>=y; i--){
                d[n-x-1][i]=data;
                data++;
            }
            
            //赋值左边
            for(int i=n-x-2; i>x; i--){
                d[i][y] = data;
                data++;
            }
            x++;
            y++;
        }
        
        vector<vector<int>> result;
        for(int i=0; i<n; i++){
            vector<int> row;
            for(int j=0; j<n; j++){
                row.push_back(d[i][j]);
            }
            result.push_back(row);
        }
        
        for(int i=0; i<n; i++){
            delete[] d[i];
        }
        delete[] d;
        
        return result;
    }
};