<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 {
    bool bfs(int i,int j,vector<vector<char>>& grid,vector<vector<int>>& vis){
        int m = grid.size();
        int n = grid[0].size();
        queue<pair<pair<int,int>,pair<int,int>>> q;
        q.push({{i,j},{-1,-1}});
        vis[i][j] = 1;

        vector<pair<int,int>> dir = {{1,0},{-1,0},{0,1},{0,-1}};
        while(!q.empty()){
            int nodei = q.front().first.first;
            int nodej = q.front().first.second;
            int parenti = q.front().second.first;
            int parentj = q.front().second.second;
            int color = grid[nodei][nodej];
            q.pop();

            for(auto it : dir){
                int nrow = nodei + it.first;
                int ncol = nodej + it.second;

                if(nrow >= 0 && ncol >= 0 && nrow < m && ncol < n && vis[nrow][ncol] && grid[nrow][ncol] == color && (nrow != parenti || ncol != parentj)){
                    return true;
                }


                if(nrow >= 0 && ncol >= 0 && nrow < m && ncol < n && !vis[nrow][ncol] && grid[nrow][ncol] == color){
                    vis[nrow][ncol] = 1;
                    q.push({{nrow,ncol},{nodei,nodej}});
                }

            }

        }
        return false;
    }
public:
    bool containsCycle(vector<vector<char>>& grid) {
        int m = grid.size();
        int n = grid[0].size();
        vector<vector<int>> vis(m,vector<int> (n,0));

        for(int i = 0 ; i < m ; i++){
            for(int j = 0 ; j < n ; j++){
                if(!vis[i][j]){
                    if(bfs(i,j,grid,vis)) return 1;
                }
            }
        }
        return 0;
        
    }
};
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