<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) {
        queue<pair<pair<int, int>, pair<int,int>>> q;
        vector<vector<bool>> visited (grid.size(), vector<bool> (grid[0].size(), false));
        for(int i=0; i<grid.size(); i++){
            for(int j=0; j<grid[0].size(); j++){
                pair<pair<int, int>, pair<int,int>> cur = make_pair(make_pair(i,j),make_pair(i,j));
                if (visited[i][j] == 1) continue;
                q.push(cur);
                while(!q.empty()){
                    pair<pair<int, int>, pair<int,int>> curcur = q.front();
                    q.pop();
                    int x = curcur.first.first;
                    int y= curcur.first.second;
                    visited[x][y] = true;
                    if(x+1>=0 && x+1<grid.size()){
                        if(grid[x+1][y] == grid[x][y]){
                            if(!visited[x+1][y]){
                                q.push(make_pair(make_pair(x+1,y),make_pair(x,y)));
                            }else{
                                if((curcur.second.first != x+1) || (curcur.second.second != y)){
                                    return true;
                                }
                            }
                        }
                    }
                    if(x-1>=0 && x-1<grid.size()){
                        if(grid[x-1][y] == grid[x][y]){
                            if(!visited[x-1][y]){
                                q.push(make_pair(make_pair(x-1,y),make_pair(x,y)));
                            }else{
                                if((curcur.second.first != x-1) || (curcur.second.second != y)){
                                    return true;
                                }
                            }
                        }
                    }
                    if(y+1>=0 && y+1<grid[0].size()){
                        if(grid[x][y+1] == grid[x][y]){
                            if(!visited[x][y+1]){
                                q.push(make_pair(make_pair(x,y+1),make_pair(x,y)));
                            }else{
                                if((curcur.second.first != x) || (curcur.second.second != y+1)){
                                    return true;
                                }
                            }
                        }
                    }
                    if(y-1>=0 && y-1<grid[0].size()){
                        if(grid[x][y-1] == grid[x][y]){
                            if(!visited[x][y-1]){
                                q.push(make_pair(make_pair(x,y-1),make_pair(x,y)));
                            }else{
                                if((curcur.second.first != x) || (curcur.second.second != y-1)){
                                    return true;
                                }
                            }
                        }
                    }
                }
            }
        }

        return false;
    }
};
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