LeetCode 0054 - Spiral Matrix

Reck Zhang

发布于 2021-08-11 10:37:11

1660

发布于 2021-08-11 10:37:11

文章被收录于专栏：Reck Zhang

Spiral Matrix

Desicription

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.

For example, Given the following matrix:

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

You should return [1,2,3,6,9,8,7,4,5].

Solution

class Solution {
private:
    int n, m;
    bool isValid(vector<vector<int> >& matrix, int x, int y){
        if(x < 0 || x >= n || y < 0 || y >= m || matrix[x][y] == INT_MIN)
            return 0;
        return 1;
    }
public:
    vector<int> spiralOrder(vector<vector<int> >& matrix) {
        vector<int> res;
        if(matrix.empty())
            return res;
        n = matrix.size();
        m = matrix[0].size();
        int x = 0;
        int y = 0;
        while(1){
            bool flag = 0;
            while(isValid(matrix, x, y))
                res.push_back(matrix[x][y]), matrix[x][y] = INT_MIN, y++, flag = 1;
            y--;
            x++;
            while(isValid(matrix, x, y))
                res.push_back(matrix[x][y]), matrix[x][y] = INT_MIN, x++, flag = 1;
            x--;
            y--;
            while(isValid(matrix, x, y))
                res.push_back(matrix[x][y]), matrix[x][y] = INT_MIN, y--, flag = 1;
            y++;
            x--;
            while(isValid(matrix, x, y))
                res.push_back(matrix[x][y]), matrix[x][y] = INT_MIN, x--, flag = 1;
            x++;
            y++;
            if(!flag)
                return res;
        }
    }
};

本文参与腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。

原始发表：2017-11-13，如有侵权请联系 cloudcommunity@tencent.com 删除

matrix