LeetCode54.螺旋矩阵

题解思路

代码

class Solution {
public:
    vector<int> spiralOrder(vector<vector<int>>& matrix) {
        vector<int> res;
        int n = matrix.size();// 行
        int m = matrix[0].size(); // 列
        vector<vector<bool>> st(n, vector<bool>(m));

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

        for(int i = 0, x = 0, y = 0, d = 0; i < n * m; i++){
            res.push_back(matrix[x][y]);
            st[x][y] = true;

            // 按照要求遍历四个方向
            int x1 = x + dx[d], y1 = y + dy[d];
            // 边界判断
            if(x1 < 0 || x1 >= n || y1 < 0 || y1 >= m || st[x1][y1]){
                // 遇到边界，就改变方向
                d = (d + 1) % 4;
                x1 = x + dx[d], y1 = y + dy[d];
            }

            x = x1, y = y1;

        }

        return res;
    }
};