Solución de Shortest Bridge Between Islands

esta es mi solución en java, primero obtengo las coordenadas de la primera isla con DFS y luego desde cada punto de la primera isla hago BFS para encontrar la distancia entre las islas ```java package dev.yojanpardo.grafosarboles.shortestbridge; import dev.yojanpardo.grafosarboles.recursion.Point; import java.util.HashSet; import java.util.LinkedList; import java.util.Queue; import java.util.Set; public class ShortestBridgeBetweenIslands { private static final Point[] DIRECTIONS = new Point[] { new Point(1,0), new Point(0,1), new Point(-1,0), new Point(0,-1) }; public static void main(String[] args) { final int[][] islandsMap = buildIslandsMap(); final Queue<Point> firstIslandCoordinates = findFirstIslandEdges(islandsMap); System.out.printf("the minimum required materials for build a bridge are: [%d]\n", calculateMinimumMaterialsForBridge(islandsMap, firstIslandCoordinates)); } private static int calculateMinimumMaterialsForBridge(int[][] islandsMap, Queue<Point> firstIslandCoordinates) { int minRequiredMaterials = -1; final Set<Point> visitedPoints = new HashSet<>(); while(!firstIslandCoordinates.isEmpty()){ int size = firstIslandCoordinates.size(); for(int i = 0; i < size; i++) { Point islandCoordinate = firstIslandCoordinates.poll(); if(islandCoordinate != null && islandsMap[islandCoordinate.getX()][islandCoordinate.getY()] == 1){ return minRequiredMaterials; } if(!visitedPoints.contains(islandCoordinate)){ visitedPoints.add(islandCoordinate); firstIslandCoordinates.addAll(getPossibleRoutesFromPoint(islandCoordinate, islandsMap)); } } minRequiredMaterials++; } return -1; } private static Queue<Point> getPossibleRoutesFromPoint(Point islandCoordinate, int[][] islandsMap) { final Queue<Point> possibleRoutes = new LinkedList<>(); for(Point direction : DIRECTIONS){ Point point = new Point(islandCoordinate.getX() + direction.getX(), islandCoordinate.getY() + direction.getY()); if(point.getX() >= 0 && point.getY() >= 0 && point.getX() < islandsMap.length && point.getY() < islandsMap[point.getX()].length ){ possibleRoutes.add(point); } } return possibleRoutes; } private static Queue<Point> findFirstIslandEdges(int[][] islandsMap) { final Queue<Point> edgePoints = new LinkedList<>(); for (int x = 0; x < islandsMap.length; x++){ for(int y = 0; y < islandsMap[x].length; y++){ if(islandsMap[x][y] == 1) { dfs(islandsMap, x, y, edgePoints); return edgePoints; } } } return edgePoints; } private static void dfs(int[][] islandsMap, int x, int y, final Queue<Point> edgePoints) { if(x < 0 || y < 0 || x >= islandsMap.length || y >= islandsMap[x].length || islandsMap[x][y] == 0){ return; } islandsMap[x][y] = 0; edgePoints.add(new Point(x,y)); for (Point direction : DIRECTIONS){ dfs(islandsMap, x + direction.getX(), y + direction.getY(), edgePoints); } } /** * builds the map with two islands * @return the array with the islands */ private static int[][] buildIslandsMap() { return new int[][] { {0,1,0,0,0,0,0}, {1,1,1,0,0,0,0}, {0,0,0,0,0,0,0}, {0,0,0,0,0,1,1}, {0,0,0,0,0,1,1}, }; } } ```