condorcet-winner/build/condorcet.js

A simple condorcet vote algorithm implementation in typescript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.condorcetWinner = condorcetWinner;
function condorcetWinner(candidates, ballots) {
    const votes = candidates.reduce((votes, candidate) => {
        votes[candidate] = 0;
        return votes;
    }, {});
    ballots.forEach((ballot) => {
        ballot.forEach((candidate, index) => {
            votes[candidate] += ballot.length - index;
        });
    });
    const sortedCandidates = candidates.sort((a, b) => votes[b] - votes[a]);
    for (let i = 0; i < sortedCandidates.length; i++) {
        const candidate = sortedCandidates[i];
        let hasBeenBeaten = false;
        for (let j = 0; j < sortedCandidates.length; j++) {
            if (i === j)
                continue;
            if (votes[candidate] <= votes[sortedCandidates[j]]) {
                hasBeenBeaten = true;
                break;
            }
        }
        if (!hasBeenBeaten) {
            return candidate;
        }
    }
    return null;
}