leetCode59. 螺旋矩阵 II

leetCode59. 螺旋矩阵 II

题目思路：见我的这篇博客

代码

class Solution {
public:
    vector<vector<int>> generateMatrix(int n) {
        // n * n的矩阵的初始化
        vector<vector<int>> res(n, vector<int> (n));

        // 方向数组
        int dx[] = {0, 1, 0, -1};
        int dy[] = {1, 0, -1, 0};

        for(int i = 1, x = 0, y = 0, d = 0; i <= n * n; i++){ // 从1开始进行填写，填写到n*n
            res[x][y] = i;
            int x1 = x + dx[d];
            int y1 = y + dy[d];
            if(x1 >= n || x1 < 0 || y1 < 0 || y1 >= n || res[x1][y1]){
                d = (d + 1) % 4;
                x1 = x + dx[d];
                y1 = y + dy[d];
            }

            x = x1, y = y1;
        }

        return res;
    }
};