Skip to content

Commit

Permalink
Merge pull request #50 from CrispyBacon1999/master
Browse files Browse the repository at this point in the history 
Fix optional argument for topological sort
  • Loading branch information
@curran
curran authored May 24, 2021
2 parents b7dc104 + cd3c39b commit 653b64e
Show file tree
Hide file tree
Showing 4 changed files with 55 additions and 81 deletions.
2 changes: 1 addition & 1 deletion index.d.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@ declare function Graph(serialized?: Serialized): {
depthFirstSearch: (sourceNodes?: string[] | undefined, includeSourceNodes?: boolean, errorOnCycle?: boolean) => string[];
hasCycle: () => boolean;
lowestCommonAncestors: (node1: NodeId, node2: NodeId) => string[];
topologicalSort: (sourceNodes: NodeId[], includeSourceNodes?: boolean) => string[];
topologicalSort: (sourceNodes?: string[] | undefined, includeSourceNodes?: boolean) => string[];
shortestPath: (source: NodeId, destination: NodeId) => string[] & {
weight?: number | undefined;
};
Expand Down
130 changes: 52 additions & 78 deletions index.js
View file
Original file line number Diff line number Diff line change
@@ -1,59 +1,41 @@
"use strict";
var __extends = (this && this.__extends) || (function () {
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; };
return extendStatics(d, b);
};
return function (d, b) {
if (typeof b !== "function" && b !== null)
throw new TypeError("Class extends value " + String(b) + " is not a constructor or null");
extendStatics(d, b);
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
})();
var CycleError = /** @class */ (function (_super) {
__extends(CycleError, _super);
function CycleError(message) {
var _this = _super.call(this, message) || this;
Object.setPrototypeOf(_this, CycleError.prototype);
return _this;
class CycleError extends Error {
constructor(message) {
super(message);
Object.setPrototypeOf(this, CycleError.prototype);
}
return CycleError;
}(Error));
}
// A graph data structure with depth-first search and topological sort.
function Graph(serialized) {
// Returned graph instance
var graph = {
addNode: addNode,
removeNode: removeNode,
nodes: nodes,
adjacent: adjacent,
addEdge: addEdge,
removeEdge: removeEdge,
hasEdge: hasEdge,
setEdgeWeight: setEdgeWeight,
getEdgeWeight: getEdgeWeight,
indegree: indegree,
outdegree: outdegree,
depthFirstSearch: depthFirstSearch,
hasCycle: hasCycle,
lowestCommonAncestors: lowestCommonAncestors,
topologicalSort: topologicalSort,
shortestPath: shortestPath,
serialize: serialize,
deserialize: deserialize
const graph = {
addNode,
removeNode,
nodes,
adjacent,
addEdge,
removeEdge,
hasEdge,
setEdgeWeight,
getEdgeWeight,
indegree,
outdegree,
depthFirstSearch,
hasCycle,
lowestCommonAncestors,
topologicalSort,
shortestPath,
serialize,
deserialize
};
// The adjacency list of the graph.
// Keys are node ids.
// Values are adjacent node id arrays.
var edges = {};
const edges = {};
// The weights of edges.
// Keys are string encodings of edges.
// Values are weights (numbers).
var edgeWeights = {};
const edgeWeights = {};
// If a serialized graph was passed into the constructor, deserialize it.
if (serialized) {
deserialize(serialized);
Expand Down Expand Up @@ -83,7 +65,7 @@ function Graph(serialized) {
// Gets the list of nodes that have been added to the graph.
function nodes() {
// TODO: Better implementation with set data structure
var nodeSet = {};
const nodeSet = {};
Object.keys(edges).forEach(function (u) {
nodeSet[u] = true;
edges[u].forEach(function (v) {
Expand All @@ -110,7 +92,7 @@ function Graph(serialized) {
// Gets the weight of the given edge.
// Returns 1 if no weight was previously set.
function getEdgeWeight(u, v) {
var weight = edgeWeights[encodeEdge(u, v)];
const weight = edgeWeights[encodeEdge(u, v)];
return weight === undefined ? 1 : weight;
}
// Adds an edge from node u to node v.
Expand Down Expand Up @@ -142,7 +124,7 @@ function Graph(serialized) {
// Computes the indegree for the given node.
// Not very efficient, costs O(E) where E = number of edges.
function indegree(node) {
var degree = 0;
let degree = 0;
function check(v) {
if (v === node) {
degree++;
Expand All @@ -163,18 +145,16 @@ function Graph(serialized) {
// include or exclude the source nodes from the result (true by default).
// If `sourceNodes` is not specified, all nodes in the graph
// are used as source nodes.
function depthFirstSearch(sourceNodes, includeSourceNodes, errorOnCycle) {
if (includeSourceNodes === void 0) { includeSourceNodes = true; }
if (errorOnCycle === void 0) { errorOnCycle = false; }
function depthFirstSearch(sourceNodes, includeSourceNodes = true, errorOnCycle = false) {
if (!sourceNodes) {
sourceNodes = nodes();
}
if (typeof includeSourceNodes !== "boolean") {
includeSourceNodes = true;
}
var visited = {};
var visiting = {};
var nodeList = [];
const visited = {};
const visiting = {};
const nodeList = [];
function DFSVisit(node) {
if (visiting[node] && errorOnCycle) {
throw new CycleError("Cycle found");
Expand Down Expand Up @@ -220,8 +200,8 @@ function Graph(serialized) {
// Inspired by https://github.com/relaxedws/lca/blob/master/src/LowestCommonAncestor.php code
// but uses depth search instead of breadth. Also uses some optimizations
function lowestCommonAncestors(node1, node2) {
var node1Ancestors = [];
var lcas = [];
const node1Ancestors = [];
const lcas = [];
function CA1Visit(visited, node) {
if (!visited[node]) {
visited[node] = true;
Expand All @@ -230,7 +210,7 @@ function Graph(serialized) {
lcas.push(node);
return false; // found - shortcut
}
return adjacent(node).every(function (node) {
return adjacent(node).every(node => {
return CA1Visit(visited, node);
});
}
Expand All @@ -245,7 +225,7 @@ function Graph(serialized) {
lcas.push(node);
}
else if (lcas.length == 0) {
adjacent(node).forEach(function (node) {
adjacent(node).forEach(node => {
CA2Visit(visited, node);
});
}
Expand All @@ -261,20 +241,19 @@ function Graph(serialized) {
// such that for each visited edge (u, v), u comes before v in the list.
// Amazingly, this comes from just reversing the result from depth first search.
// Cormen et al. "Introduction to Algorithms" 3rd Ed. p. 613
function topologicalSort(sourceNodes, includeSourceNodes) {
if (includeSourceNodes === void 0) { includeSourceNodes = true; }
function topologicalSort(sourceNodes, includeSourceNodes = true) {
return depthFirstSearch(sourceNodes, includeSourceNodes, true).reverse();
}
// Dijkstra's Shortest Path Algorithm.
// Cormen et al. "Introduction to Algorithms" 3rd Ed. p. 658
// Variable and function names correspond to names in the book.
function shortestPath(source, destination) {
// Upper bounds for shortest path weights from source.
var d = {};
const d = {};
// Predecessors.
var p = {};
const p = {};
// Poor man's priority queue, keyed on d.
var q = {};
let q = {};
function initializeSingleSource() {
nodes().forEach(function (node) {
d[node] = Infinity;
Expand All @@ -299,8 +278,8 @@ function Graph(serialized) {
}
// Linear search to extract (find and remove) min from q.
function extractMin() {
var min = Infinity;
var minNode;
let min = Infinity;
let minNode;
Object.keys(q).forEach(function (node) {
if (d[node] < min) {
min = d[node];
Expand All @@ -316,7 +295,7 @@ function Graph(serialized) {
return minNode;
}
function relax(u, v) {
var w = getEdgeWeight(u, v);
const w = getEdgeWeight(u, v);
if (d[v] > d[u] + w) {
d[v] = d[u] + w;
p[v] = u;
Expand All @@ -325,26 +304,21 @@ function Graph(serialized) {
function dijkstra() {
initializeSingleSource();
initializePriorityQueue();
var _loop_1 = function () {
var u = extractMin();
while (!priorityQueueEmpty()) {
const u = extractMin();
if (u === null)
return { value: void 0 };
return;
adjacent(u).forEach(function (v) {
relax(u, v);
});
};
while (!priorityQueueEmpty()) {
var state_1 = _loop_1();
if (typeof state_1 === "object")
return state_1.value;
}
}
// Assembles the shortest path by traversing the
// predecessor subgraph from destination to source.
function path() {
var nodeList = [];
var weight = 0;
var node = destination;
const nodeList = [];
let weight = 0;
let node = destination;
while (p[node]) {
nodeList.push(node);
weight += getEdgeWeight(p[node], node);
Expand All @@ -363,14 +337,14 @@ function Graph(serialized) {
}
// Serializes the graph.
function serialize() {
var serialized = {
const serialized = {
nodes: nodes().map(function (id) {
return { id: id };
}),
links: []
};
serialized.nodes.forEach(function (node) {
var source = node.id;
const source = node.id;
adjacent(source).forEach(function (target) {
serialized.links.push({
source: source,
Expand Down
2 changes: 1 addition & 1 deletion index.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -288,7 +288,7 @@ function Graph(serialized?: Serialized) {
// Amazingly, this comes from just reversing the result from depth first search.
// Cormen et al. "Introduction to Algorithms" 3rd Ed. p. 613
function topologicalSort(
sourceNodes: NodeId[],
sourceNodes?: NodeId[],
includeSourceNodes: boolean = true
) {
return depthFirstSearch(sourceNodes, includeSourceNodes, true).reverse();
Expand Down
2 changes: 1 addition & 1 deletion tsconfig.json
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@
"noImplicitReturns": true,
"noImplicitThis": true,
"strict": true,
"target": "ES5",
"target": "ES2016",
"strictFunctionTypes": true,
"strictNullChecks": true,
"downlevelIteration": true,
Expand Down

0 comments on commit 653b64e

Please sign in to comment.