<p>There is a strange printer with the following two special requirements:</p>

<ul>
	<li>On each turn, the printer will print a solid rectangular pattern of a single color on the grid. This will cover up the existing colors in the rectangle.</li>
	<li>Once the printer has used a color for the above operation, <strong>the same color cannot be used again</strong>.</li>
</ul>

<p>You are given a <code>m x n</code> matrix <code>targetGrid</code>, where <code>targetGrid[row][col]</code> is the color in the position <code>(row, col)</code> of the grid.</p>

<p>Return <code>true</code><em> if it is possible to print the matrix </em><code>targetGrid</code><em>,</em><em> otherwise, return </em><code>false</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/12/23/print1.jpg" style="width: 600px; height: 175px;" />
<pre>
<strong>Input:</strong> targetGrid = [[1,1,1,1],[1,2,2,1],[1,2,2,1],[1,1,1,1]]
<strong>Output:</strong> true
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/12/23/print2.jpg" style="width: 600px; height: 367px;" />
<pre>
<strong>Input:</strong> targetGrid = [[1,1,1,1],[1,1,3,3],[1,1,3,4],[5,5,1,4]]
<strong>Output:</strong> true
</pre>

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

<pre>
<strong>Input:</strong> targetGrid = [[1,2,1],[2,1,2],[1,2,1]]
<strong>Output:</strong> false
<strong>Explanation:</strong> It is impossible to form targetGrid because it is not allowed to print the same color in different turns.
</pre>

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

<ul>
	<li><code>m == targetGrid.length</code></li>
	<li><code>n == targetGrid[i].length</code></li>
	<li><code>1 &lt;= m, n &lt;= 60</code></li>
	<li><code>1 &lt;= targetGrid[row][col] &lt;= 60</code></li>
</ul>

class Solution {
public:
    bool isFound(vector<vector<int>> &graph){
        vector<int> indegree(graph.size(), 0);
        for(int i = 0; i < graph.size(); i++){
            for(auto it: graph[i]){
                indegree[it]++;
            }
        }
        
        set<int> s;
        for(int i = 0; i < graph.size(); i++){
            if(indegree[i] == 0){
                s.insert(i);
            }
        }
        
        vector<int> vis(graph.size(), 0);
        while(!s.empty()){
            int node = *s.begin();
            s.erase(s.begin());
            vis[node] = 1;
            for(auto it: graph[node]){
                if(indegree[it] > 0)
                    indegree[it]--;
                if(indegree[it] == 0){
                    s.insert(it);
                }
            }
        }
        
        for(int i = 0; i < graph.size(); i++){
            if(vis[i] == 0){
                return false;
            }
        }
        return true;
    }
    
    bool isPrintable(vector<vector<int>>& targetGrid) {
        map<int, pair<pair<int, int>, pair<int, int>>> mp;
        int n = targetGrid.size();
        int m = targetGrid[0].size();
        set<int> count;
        
        for(int i = 0; i < targetGrid.size(); i++){
            for(int j = 0; j < targetGrid[0].size(); j++){
                count.insert(targetGrid[i][j]);
            }
        }
        
        for(auto it: count){
            mp[it] = {{INT_MAX, INT_MIN}, {INT_MAX, INT_MIN}};
        }
        
        for(auto color: count){
            for(int j = 0; j < n; j++){
                for(int k = 0; k < m; k++){
                    if(targetGrid[j][k] == color){
                        mp[color].first.first = min(mp[color].first.first, j);
                        mp[color].first.second = max(mp[color].first.second, j);
                        mp[color].second.first = min(mp[color].second.first, k);
                        mp[color].second.second = max(mp[color].second.second, k);
                    }
                }
            }
        }
        
        vector<vector<int>> graph(*count.rbegin(),vector<int>());
        for(auto it: mp){
            set<int> vis;
            for(int i = it.second.first.first; i <= it.second.first.second; i++){
                for(int j = it.second.second.first; j <= it.second.second.second; j++){
                    if(it.first != targetGrid[i][j]){
                        if(vis.find(targetGrid[i][j]) != vis.end()) continue;
                        graph[it.first-1].push_back(targetGrid[i][j]-1);
                        vis.insert(targetGrid[i][j]);
                    }
                }
            }
        }
        
        if(isFound(graph)){
            return true;
        }
        return false;
    }
};

27739