From 411af3e6201b0cc494cda9f5d27d7b5204efc591 Mon Sep 17 00:00:00 2001
From: skhourshed2 <skhourshed2@huskers.unl.edu>
Date: Sun, 29 Sep 2024 10:42:36 -0500
Subject: [PATCH] implemented solveByAStar and heurisitic functions
---
graph-search/src/features/maze/solvers.js | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/graph-search/src/features/maze/solvers.js b/graph-search/src/features/maze/solvers.js
index c6f67cf..a8b5850 100644
--- a/graph-search/src/features/maze/solvers.js
+++ b/graph-search/src/features/maze/solvers.js
@@ -72,7 +72,7 @@ export function solveByDijkstras(maze) {
}
function heuristic(maze, cell) {
- return 0; // TODO: stub
+ return Math.abs(maze.exit.x - cell.x) + Math.abs(maze.exit.y - cell.y);
}
export function solveByAStar(maze) {
@@ -80,33 +80,28 @@ export function solveByAStar(maze) {
const worklist = new PriorityQueue();
worklist.insert(
new Edge(undefined, maze.entrance, 0),
- 0 + heuristic(maze.entrance, maze.exit),
+ 0 + heuristic(maze, maze.exit),
);
while (worklist.size > 0) {
const workitem = worklist.remove();
- if (backpointers.has(workitem.to) &&
- backpointers.get(workitem.to).distance <= workitem.distance) {
+ if (backpointers.has(workitem.to)) {
continue;
}
workitem.to.type = CellType.CONSIDERED;
backpointers.set(workitem.to, workitem);
if (workitem.to === maze.exit) {
- const reversedPath = [];
for (let current = maze.exit;
current !== undefined;
current = backpointers.get(current).from) {
- reversedPath.push(current);
current.type = CellType.SOLUTION;
}
- return reversedPath.reverse();
+ return;
}
- for (const incidence of workitem.to.neighbors) {
+ for (const neighbor of workitem.to.neighbors) {
worklist.insert(
- new Edge(workitem.to, incidence.destination, workitem.distance),
- workitem.distance +
- heuristic(incidence.destination, maze.exit),
+ new Edge(workitem.to, neighbor, workitem.distance + 1),
+ workitem.distance + 1 + heuristic(maze, neighbor),
);
}
}
- return undefined;
}
--
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