You are given an integer n representing the number of nodes in a directed graph, with nodes labeled from $0$ to n $- 1$. You are also given two $2$D integer arrays, redEdges and blueEdges, where:

• redEdges[i] = [a_i, b_i] indicates a directed red edge from node a_i to node b_i.

• blueEdges[j] = [u_j, v_j] indicates a directed blue edge from node u_j to node v_j.

Find the shortest path from node $0$ to each node x such that the colors of the edges along the path strictly alternate between red and blue.

Return an array answer of length n, where answer[x] is the length of the shortest alternating path from node $0$ to node x, or $-1$ if no valid path exists.

Constraints:

• $1 \leq$ n $\leq 100$

• $0 \leq$ redEdges.length, blueEdges.length $\leq 400$

• redEdges[i].length $==$ blueEdges[j].length $== 2$

• $0 \leq$ a_i, b_i, u_j, v_j $<$ n

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.