How can code be developed to determine the briefest route using Breadth First Search?

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To develop code to determine the briefest route using Breadth First Search, follow these steps:

1. Define the problem: determine the starting and ending points, and the graph or map of possible routes between them.

2. Create an empty queue and add the starting point to it.

3. Create a visited set, which will keep track of the points that have already been visited, and add the starting point to it.

4. Create a parent dictionary, which will keep track of the parent of each point in the graph or map, and set the starting point's parent to None.

5. While the queue is not empty, pop the first element and check if it is the ending point. If it is, return the path from the starting point to the ending point using the parent dictionary.

6. If it is not, find all neighbors of the current point that have not been visited yet, and add them to the queue, visited set, and parent dictionary.

7. Repeat steps 5-6 until the ending point is found or the queue is empty.

Here is a sample implementation in Python:

def bfs_shortest_path(graph, start, end):
    queue = [start]
    visited = set([start])
    parent = {start: None}

    while queue:
        current = queue.pop(0)
        if current == end:
            # construct the path using parent dictionary
            path = [current]
            while parent[current] is not None:
                current = parent[current]
                path.append(current)
            return path[::-1]
        else:
            for neighbor in graph[current]:
                if neighbor not in visited:
                    queue.append(neighbor)
                    visited.add(neighbor)
                    parent[neighbor] = current

    return None # no path found

Note that graph is a dictionary where the keys are the points in the graph or map, and the values are lists of neighbors for each point. For example, graph = {'A': ['B', 'C'], 'B': ['A', 'D'], 'C': ['A', 'D'], 'D': ['B', 'C', 'E'], 'E': ['D']} represents a simple graph with five points and four edges. The start and end parameters are the starting and ending points. The function returns a list of points representing the shortest path from start to end, or None if no path is found.