733. Flood Fill

733. Flood Fill
【思路】

• 使用深度遍历

    vector<vector<int>> floodFill(vector<vector<int>>& image, int sr, int sc, int newColor) {
        if(image[sr][sc] != newColor)
            dfs(image,sr,sc,image[sr][sc],newColor);
        return image;
           
        
    }
    
    void dfs(vector<vector<int>>& image, int i, int j, int old,int newcolor){
        if(i<0 || j<0 || i>= image.size() || j >=image[0].size()|| image[i][j] != old ) return;
        image[i][j] = newcolor;
        dfs(image, i, j - 1, old, newcolor);
        dfs(image, i, j + 1, old, newcolor);
        dfs(image, i - 1, j, old, newcolor);
        dfs(image, i + 1, j, old, newcolor);
             
    }