Leetcode 130. 被围绕的区域（DAY 160）---- LeetCode 精选 TOP 面试题

心已赠人 2022-09-10 03:14 133阅读 0赞

### 文章目录 ###

*   *  原题题目
     *  代码实现（首刷自解）

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## 原题题目 ##

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![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBATG92ZSA2_size_20_color_FFFFFF_t_70_g_se_x_16]

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## 代码实现（首刷自解） ##

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class Solution { 
    public:
        void solvehelper(vector<vector<bool>>& visit,vector<vector<char>>& board,int x,int y)
        { 
            if(x < 0 || y < 0 || x >= board.size() || y >= board[0].size() || visit[x][y] || board[x][y] == 'X')    return;    
            visit[x][y] = true; 
            int num = 1;
            for(int i=0;i<4;++i)
            { 
                if(i<=1) solvehelper(visit,board,x+num,y);
                else     solvehelper(visit,board,x,y+num);
                num *= -1;
            }
            return;
        }
    
        void solve(vector<vector<char>>& board) { 
            vector<vector<bool>> visit(board.size(),vector<bool> (board[0].size(),false));
            for(int i=0;i<board.size();++i)
            { 
                for(int j=0;j<board[0].size();++j)
                { 
                    if(!i || i == board.size()-1 || !j || j == board[0].size()-1)
                        solvehelper(visit,board,i,j);
                }
            }
            
            for(int i=1;i<board.size()-1;++i)
            { 
                for(int j=1;j<board[0].size()-1;++j)
                { 
                    if(board[i][j] == 'O' && !visit[i][j])
                        board[i][j] = 'X';
                }
            }
        }
    };

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBATG92ZSA2_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220829/1623ee6092b849df925d6e5d0293cda5.png