maxCliqueByBronKerbosch.hhs

function maxCliqueByBronKerbosch(edges) {
    //Input: a set of edges representing undirected graph G = (V,E)
    //Output: all max cliques of graph G using Bron-Kerbosch algorithm
    //Reference:
    //https://github.com/SeregPie/BronKerbosch
    function Set_intersection(set, otherSet) {
        let result = new Set();
        otherSet.forEach(value => {
            if (set.has(value)) {
                result.add(value);
            }
        });
        return result;
    }
    
    function Set_difference(set, otherSet) {
        let result = new Set(set);
        otherSet.forEach(value => {
            result.delete(value);
        });
        return result;
    }
    
    function Set_union (set, otherSet) {
        let result = new Set(set);
        otherSet.forEach(value => {
            result.add(value);
        });
        return result;
    }

    function bind_recursive(that) {
        let recur = function(...args) {
            return that.call(this, recur, ...args);
        };
        return recur;
    }
	edges = Array.from(edges);
	let nodes = new Set();
	edges.forEach(edge => {
		nodes.add(edge[0]).add(edge[1]);
	});
	if (nodes.size < 2) {
		return [];
	}
	let neighbors = new Map();
	nodes.forEach(node => {
		neighbors.set(node, new Set());
	});
	edges.forEach(edge => {
		neighbors.get(edge[0]).add(edge[1]);
		neighbors.get(edge[1]).add(edge[0]);
	});
	let cliques = [];
	bind_recursive((recur, clique, candidates, excludedCandidates) => {
		if (!candidates.size && !excludedCandidates.size) {
			cliques.push(Array.from(clique));
		}
		let pivotNeighbors = new Set();
		Set_union(candidates, excludedCandidates).forEach(candidate => {
			let t = Set_intersection(neighbors.get(candidate), candidates);
			if (t.size > pivotNeighbors.size) {
				pivotNeighbors = t;
			}
		});
		Set_difference(candidates, pivotNeighbors).forEach(candidate => {
			let candidateNeighbors = neighbors.get(candidate);
			recur((new Set(clique)).add(candidate), Set_intersection(candidates, candidateNeighbors), Set_intersection(excludedCandidates, candidateNeighbors));
			candidates.delete(candidate);
			excludedCandidates.add(candidate);
		});
	})(new Set(), nodes, new Set());
	return cliques;
}