<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:
    unordered_map<int, vector<int>> red_adj;
    unordered_map<int, vector<int>> blue_adj;
    int visited_red[101];
    int visited_blue[101];
    vector<int> shortestAlternatingPaths(int n, vector<vector<int>>& redEdges, vector<vector<int>>& blueEdges) {
        for (int i=0; i<redEdges.size(); i++) {
            red_adj[redEdges[i][0]].push_back(redEdges[i][1]);
        }
        for (int i=0; i<blueEdges.size(); i++) {
            blue_adj[blueEdges[i][0]].push_back(blueEdges[i][1]);
        }

        vector<int> ans(n, -1);

        for (int i=0; i<n; i++) {
            memset(visited_red, 0, sizeof(visited_red));
            memset(visited_blue, 0, sizeof(visited_blue));

            queue<pair<pair<int, int>, int>> que;
            
            que.push({{0, 'r'}, 0});
            que.push({{0, 'b'}, 0}); 
            
            while (!que.empty()) {
                int j = que.front().first.first;
                int c = que.front().first.second;
                int dist = que.front().second;
                que.pop();
                if (j == i) {
                    ans[i] = dist;
                    break;
                }
                
                if (c == 'r') {
                    if (visited_red[j]) continue;
                    visited_red[j] = 1;

                    for (int k=0; k<red_adj[j].size(); k++) {
                        que.push({{red_adj[j][k], (int)'b'}, dist+1});
                    }
                }
                else {
                    if (visited_blue[j]) continue;
                    visited_blue[j] = 1;

                    for (int k=0; k<blue_adj[j].size(); k++) {
                        que.push({{blue_adj[j][k], (int)'r'}, dist+1});
                    }
                }
            }
        }

        return ans;
    }
};


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