<p>You are given an integer <code>n</code>, the number of nodes in a directed graph where the nodes are labeled from <code>0</code> to <code>n - 1</code>. Each edge is red or blue in this graph, and there could be self-edges and parallel edges.</p>

<p>You are given two arrays <code>redEdges</code> and <code>blueEdges</code> where:</p>

<ul>
	<li><code>redEdges[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> indicates that there is a directed red edge from node <code>a<sub>i</sub></code> to node <code>b<sub>i</sub></code> in the graph, and</li>
	<li><code>blueEdges[j] = [u<sub>j</sub>, v<sub>j</sub>]</code> indicates that there is a directed blue edge from node <code>u<sub>j</sub></code> to node <code>v<sub>j</sub></code> in the graph.</li>
</ul>

<p>Return an array <code>answer</code> of length <code>n</code>, where each <code>answer[x]</code> is the length of the shortest path from node <code>0</code> to node <code>x</code> such that the edge colors alternate along the path, or <code>-1</code> if such a path does not exist.</p>

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

<pre>
<strong>Input:</strong> n = 3, redEdges = [[0,1],[1,2]], blueEdges = []
<strong>Output:</strong> [0,1,-1]
</pre>

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

<pre>
<strong>Input:</strong> n = 3, redEdges = [[0,1]], blueEdges = [[2,1]]
<strong>Output:</strong> [0,1,-1]
</pre>

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

<ul>
	<li><code>1 &lt;= n &lt;= 100</code></li>
	<li><code>0 &lt;= redEdges.length,&nbsp;blueEdges.length &lt;= 400</code></li>
	<li><code>redEdges[i].length == blueEdges[j].length == 2</code></li>
	<li><code>0 &lt;= a<sub>i</sub>, b<sub>i</sub>, u<sub>j</sub>, v<sub>j</sub> &lt; n</code></li>
</ul>

class Solution {
public:
    vector<int> shortestAlternatingPaths(int n, vector<vector<int>>& redEdges, vector<vector<int>>& blueEdges) {
        queue<vector<int>>q;
        vector<vector<int>> seen(n, vector<int> (3, 0));
        map<int, vector<int>> red;
        map<int, vector<int>> blue;
        for(auto edge: redEdges) {
            int a = edge[0];
            int b = edge[1];
            red[a].push_back(b);
        }
        for(auto edge: blueEdges) {
            int a = edge[0];
            int b = edge[1];
            blue[a].push_back(b);
        }
        q.push({0, -1, 0});
        q.push({0, 1, 0});
        seen[0][0] = 1;
        seen[0][2] = 1;
        vector<int> res (n, -1);
        res[0] = 0;
        while(q.size() > 0) {
            auto front = q.front();
            q.pop();
            int node = front[0];
            int color = front[1];
            int dist = front[2];

            if(color == -1) {
                auto it = blue.find(node);
                if(it != blue.end()) {
                    for(int x: it->second) {
                        if(res[x] == -1) {
                            res[x] = dist + 1; // issue was i was updating best answer via 
                            // saved answer but this doesn't take into account the state, not
                            //  just the node but also the node colour combo 
                        }
                        if(seen[x][color+1] == 0) {
                            seen[x][color+1] = 1;
                            q.push({x, color*-1, dist + 1});
                        }
                    }
                }
            }
            if(color == 1) {
                auto it = red.find(node);
                if(it != red.end()) {
                    for(int x: it->second) {
                        if(res[x] == -1) {
                            res[x] = dist+1; 
                        }
                        if(seen[x][color+1] == 0) { // ****
                            seen[x][color+1] = 1;
                            q.push({x, color*-1, dist+1});
                        }
                    }
                }
            }
        }
        return res;
    }
};
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