Java program to implement to implement A* algorithm (AI)

import java.util.Iterator; import org.json.JSONObject; public class Tree { String s = "{" +"\"s\" : { \"a\": 1, \"b\":2 }," +"\"a\": {\"y\": 7, \"z\": 4}," +"\"b\": {\"c\": 7, \"d\": 1}," +"\"y\": {\"e\": 3}," +"\"z\": {\"e\": 2}," +"\"c\": {\"e\": 5}," +"\"d\": {\"e\": 12}," +"\"e\": 0" +"}"; String h_str ="{" +"\"s\" : 10," +"\"a\" : 5," +"\"b\" : 6," +"\"c\" : 4," +"\"d\" : 15," +"\"z\" : 5," +"\"y\" : 8," +"\"e\" : 0," +"}"; JSONObject graph = new JSONObject(s); JSONObject h = new JSONObject(h_str); JSONObject list_1 = new JSONObject(); JSONObject list_2 = new JSONObject(); String root = "s"; String goal = "e"; public void astar(String node, String f, int g) { // System.out.println(f+" "+g); try { Iterator itr = graph.getJSONObject(node).keySet().iterator(); while(itr.hasNext()) { String e = (String)itr.next(); // System.out.println(); if (e != root) { list_1.put(f, g+h.getInt(node)); astar(e,f+"-"+e,g+graph.getJSONObject(node).getInt(e)); }else { System.out.println(node); } } }catch(Exception e){ list_2.put(f, g); } } } public class Run { public static void main(String args[]) { Tree a = new Tree(); a.astar(a.root, a.root, 0); System.out.println("Traversed paths -> "); Iterator itr = a.list_1.keySet().iterator(); while(itr.hasNext()) { String key = (String)itr.next(); System.out.println(key+" -> "+a.list_1.get(key)); } String p = null; int v = 1000; System.out.println("Successfull paths found ->"); Iterator itr2 = a.list_2.keySet().iterator(); while(itr2.hasNext()) { String key = (String)itr2.next(); System.out.println(key+" -> "+a.list_2.getInt(key)); if (a.list_2.getInt(key)<v) { v = a.list_2.getInt(key); p = key; } } System.out.print("The shortest path is : ("); System.out.print(p+") with value: "+v); } }

Output ->

Traversed paths -> s -> 10 s-b-c -> 13 s-b-d -> 18 s-a -> 6 s-a-y -> 16 s-b -> 8 s-a-z -> 10 Successfull paths found -> s-b-d-e -> 15 s-b-c-e -> 14 s-a-y-e -> 11 s-a-z-e -> 7 The shortest path is : (s-a-z-e) with value: 7