<p>Given a 2D array of characters <code>grid</code> of size <code>m x n</code>, you need to find if there exists any cycle consisting of the <strong>same value</strong> in <code>grid</code>.</p>

<p>A cycle is a path of <strong>length 4 or more</strong> in the grid that starts and ends at the same cell. From a given cell, you can move to one of the cells adjacent to it - in one of the four directions (up, down, left, or right), if it has the <strong>same value</strong> of the current cell.</p>

<p>Also, you cannot move to the cell that you visited in your last move. For example, the cycle <code>(1, 1) -&gt; (1, 2) -&gt; (1, 1)</code> is invalid because from <code>(1, 2)</code> we visited <code>(1, 1)</code> which was the last visited cell.</p>

<p>Return <code>true</code> if any cycle of the same value exists in <code>grid</code>, otherwise, return <code>false</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<p><strong><img alt="" src="https://assets.leetcode.com/uploads/2020/07/15/1.png" style="width: 231px; height: 152px;" /></strong></p>

<pre>
<strong>Input:</strong> grid = [[&quot;a&quot;,&quot;a&quot;,&quot;a&quot;,&quot;a&quot;],[&quot;a&quot;,&quot;b&quot;,&quot;b&quot;,&quot;a&quot;],[&quot;a&quot;,&quot;b&quot;,&quot;b&quot;,&quot;a&quot;],[&quot;a&quot;,&quot;a&quot;,&quot;a&quot;,&quot;a&quot;]]
<strong>Output:</strong> true
<strong>Explanation: </strong>There are two valid cycles shown in different colors in the image below:
<img alt="" src="https://assets.leetcode.com/uploads/2020/07/15/11.png" style="width: 225px; height: 163px;" />
</pre>

<p><strong class="example">Example 2:</strong></p>

<p><strong><img alt="" src="https://assets.leetcode.com/uploads/2020/07/15/22.png" style="width: 236px; height: 154px;" /></strong></p>

<pre>
<strong>Input:</strong> grid = [[&quot;c&quot;,&quot;c&quot;,&quot;c&quot;,&quot;a&quot;],[&quot;c&quot;,&quot;d&quot;,&quot;c&quot;,&quot;c&quot;],[&quot;c&quot;,&quot;c&quot;,&quot;e&quot;,&quot;c&quot;],[&quot;f&quot;,&quot;c&quot;,&quot;c&quot;,&quot;c&quot;]]
<strong>Output:</strong> true
<strong>Explanation: </strong>There is only one valid cycle highlighted in the image below:
<img alt="" src="https://assets.leetcode.com/uploads/2020/07/15/2.png" style="width: 229px; height: 157px;" />
</pre>

<p><strong class="example">Example 3:</strong></p>

<p><strong><img alt="" src="https://assets.leetcode.com/uploads/2020/07/15/3.png" style="width: 183px; height: 120px;" /></strong></p>

<pre>
<strong>Input:</strong> grid = [[&quot;a&quot;,&quot;b&quot;,&quot;b&quot;],[&quot;b&quot;,&quot;z&quot;,&quot;b&quot;],[&quot;b&quot;,&quot;b&quot;,&quot;a&quot;]]
<strong>Output:</strong> false
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>m == grid.length</code></li>
	<li><code>n == grid[i].length</code></li>
	<li><code>1 &lt;= m, n &lt;= 500</code></li>
	<li><code>grid</code> consists only of lowercase English letters.</li>
</ul>

class Solution
{
public:
    bool containsCycle(vector<vector<char>> &grid)
    {
        int m = grid.size(), n = grid[0].size(), i, j, k;
        bool ans = false;
        queue<vector<int>> q;
        vector<int> tmp;
        char c;
        for (i = 0; i < m; i++)
        {
            for (j = 0; j < n; j++)
            {

                if (grid[i][j] != '#')
                {
                    // cout<<i<<" "<<j<<endl;
                    q.push({i, j});
                    c = grid[i][j];
                    while (!q.empty())
                    {
                        k = q.size();
                        while (k--)
                        {
                            tmp = q.front();
                            if (grid[tmp[0]][tmp[1]] == '#')
                            {
                                ans = true;
                            }
                            grid[tmp[0]][tmp[1]] = '#';
                            q.pop();
                            if (tmp[0] + 1 < m && grid[tmp[0] + 1][tmp[1]] == c)
                            {
                                q.push({tmp[0] + 1, tmp[1]});
                            }
                            if (tmp[0] - 1 >= 0 && grid[tmp[0] - 1][tmp[1]] == c)
                            {
                                q.push({tmp[0] - 1, tmp[1]});
                            }
                            if (tmp[1] + 1 < n && grid[tmp[0]][tmp[1] + 1] == c)
                            {
                                q.push({tmp[0], tmp[1] + 1});
                            }
                            if (tmp[1] - 1 >= 0 && grid[tmp[0]][tmp[1] - 1] == c)
                            {
                                q.push({tmp[0], tmp[1] - 1});
                            }
                        }
                    }
                }
            }
        }
        return ans;
    }
};
137484