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| 1 | +package me.premaseem.datastructure.graph; |
| 2 | + |
| 3 | + |
| 4 | +import java.util.ArrayList; |
| 5 | +import java.util.LinkedList; |
| 6 | +import java.util.List; |
| 7 | + |
| 8 | +class City { |
| 9 | + int index; |
| 10 | + String name; |
| 11 | + String code; |
| 12 | + LinkedList<City> connectedCity = new LinkedList<>(); |
| 13 | + |
| 14 | + public City(int i, String name, String code) { |
| 15 | + index = i; |
| 16 | + this.name = name; |
| 17 | + this.code = code; |
| 18 | + } |
| 19 | +} |
| 20 | + |
| 21 | +public class AirlineGraph { |
| 22 | + |
| 23 | + int size =0; |
| 24 | + List<City> cities = new ArrayList<>(); |
| 25 | + |
| 26 | + void addCity(String code, String name){ |
| 27 | + int i = size++; |
| 28 | + City city = new City(i,name, code); |
| 29 | + cities.add(city); |
| 30 | + } |
| 31 | + |
| 32 | + City cityLookup(String code){ |
| 33 | + for(City c:cities){ |
| 34 | + if(c.code.equalsIgnoreCase(code)){ |
| 35 | + return c; |
| 36 | + } |
| 37 | + } |
| 38 | + return null; |
| 39 | + } |
| 40 | + |
| 41 | + void connectCity(String code1, String code2){ |
| 42 | + City c1 = cityLookup(code1); |
| 43 | + City c2 = cityLookup(code2); |
| 44 | + if( c1 == null || c2 == null){ |
| 45 | + System.out.println("Cannot connect, Invalid city code."); |
| 46 | + return; |
| 47 | + } |
| 48 | + c1.connectedCity.add(c2); |
| 49 | + } |
| 50 | + |
| 51 | + |
| 52 | + public static void main(String[] args) { |
| 53 | + |
| 54 | + AirlineGraph g = new AirlineGraph(); |
| 55 | + |
| 56 | + // Add vertex or cities in the air line graph |
| 57 | + g.addCity("SFO","San Fransisco"); |
| 58 | + g.addCity("AUS","Austin"); |
| 59 | + g.addCity("NY","New york"); |
| 60 | + g.addCity("BOM","Mumbai"); |
| 61 | + g.addCity("IND","Indore"); |
| 62 | + g.addCity("DEW","Dewas"); |
| 63 | + |
| 64 | + // Add edges or air ways in the graph |
| 65 | + g.connectCity("DEW","IND"); |
| 66 | + g.connectCity("IND", "BOM"); |
| 67 | + g.connectCity("BOM","NY"); |
| 68 | + g.connectCity("BOM","SFO"); |
| 69 | + g.connectCity("NY", "AUS"); |
| 70 | + g.connectCity("NY", "SFO"); |
| 71 | + g.connectCity("NY", "BOM"); |
| 72 | + |
| 73 | + // DFS to find path |
| 74 | + g.findDFSpath("DEW"); |
| 75 | + g.findDFSpath("NY"); |
| 76 | + |
| 77 | + // BFS to find path |
| 78 | + g.findBFSpath("DEW"); |
| 79 | + g.findBFSpath("NY"); |
| 80 | + |
| 81 | + |
| 82 | + } |
| 83 | + |
| 84 | + |
| 85 | + private void findBFSpath(String code) { |
| 86 | + boolean[] visited = new boolean[size]; |
| 87 | + City city = cityLookup(code); |
| 88 | + System.out.println("\n printing BFS path from city "+ city.name); |
| 89 | + LinkedList<City> q = new LinkedList<>(); |
| 90 | + q.add(city); |
| 91 | + visited[city.index] = true; |
| 92 | + |
| 93 | + while(!q.isEmpty()){ |
| 94 | + City currentCity = q.poll(); |
| 95 | + System.out.print(" >> "+ currentCity.name); |
| 96 | + |
| 97 | + |
| 98 | + for(City cc:currentCity.connectedCity){ |
| 99 | + if(!visited[cc.index]){ |
| 100 | + visited[cc.index] = true; |
| 101 | + q.add(cc); |
| 102 | + } |
| 103 | + } |
| 104 | + |
| 105 | + |
| 106 | + } |
| 107 | + |
| 108 | + } |
| 109 | + |
| 110 | + private void findDFSpath(String code) { |
| 111 | + boolean[] visited = new boolean[size]; |
| 112 | + City city = cityLookup(code); |
| 113 | + System.out.println("printing DFS path from city "+ city.name); |
| 114 | + DFS(city, visited); |
| 115 | + } |
| 116 | + |
| 117 | + private void DFS(City city, boolean[] visited) { |
| 118 | + visited[city.index] = true; |
| 119 | + for(City c :city.connectedCity){ |
| 120 | + if(!visited[c.index]){ |
| 121 | + DFS(c,visited); |
| 122 | + } |
| 123 | + } |
| 124 | + System.out.println(" >> "+city.name); |
| 125 | + } |
| 126 | + |
| 127 | + |
| 128 | +} |
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