59 lines
1.4 KiB
JavaScript
59 lines
1.4 KiB
JavaScript
const roads = [
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"Alice's House-Bob's House", "Alice's House-Cabin",
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"Alice's House-Post Office", "Bob's House-Town Hall",
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"Daria's House-Ernie's House", "Daria's House-Town Hall",
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"Ernie's House-Grete's House", "Grete's House-Farm",
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"Grete's House-Shop", "Marketplace-Farm",
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"Marketplace-Post Office", "Marketplace-Shop",
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"Marketplace-Town Hall", "Shop-Town Hall"
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];
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function buildGraph(edges) {
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let graph = Object.create(null);
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function addEdge(from, to) {
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if (graph[from] == null) {
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graph[from] = [to];
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} else {
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graph[from].push(to);
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}
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}
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for (let [from, to] of edges.map(r => r.split("-"))) {
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addEdge(from, to);
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addEdge(to, from);
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}
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return graph;
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}
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const roadGraph = buildGraph(roads);
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class VillageState {
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constructor(place, parcels) {
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this.place = place;
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this.parcels = parcels;
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}
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move(destination) {
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if (!roadGraph[this.place].includes(destination)) {
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return this;
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} else {
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let parcels = this.parcels.map(p => {
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if (p.place != this.place) return p;
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return { place: destination, address: p.address };
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}).filter(p => p.place != p.address);
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return new VillageState(destination, parcels);
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}
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}
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}
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let first = new VillageState(
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"Post Office",
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[{ place: "Post Office", address: "Alice's House" }]
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);
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let next = first.move("Alice's House");
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console.log(next.place);
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// → Alice's House
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console.log(next.parcels);
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// → []
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console.log(first.place);
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// → Post Office
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