score_postcodes.ts

import * as fs from "fs";
import * as path from "path";
import * as csv from "fast-csv";

interface NumberScore {
  scores: number[];
  remainingString: string;
}

const extractNumbers = (input: string): NumberScore => {
  const results = input.match(/[0-9]+/g);
  const remainingString = input.replace(/[0-9]+/g, "");
  const scores = results.map((e) => parseInt(e, 10));
  return { remainingString, scores };
};

const letterScore = (l: string): number => l.toUpperCase().charCodeAt(0) - 64;
const add = (prev: number, curr: number) => prev + curr;
const computeScore = (input: string): number => {
  const { scores, remainingString } = extractNumbers(input);

  const letterScores = remainingString
    .split("")
    .filter((e) => e.match(/\w/gi))
    .map((e) => letterScore(e));
  return [...scores, ...letterScores].reduce(add);
};

fs.createReadStream(path.resolve(__dirname, "output.csv"))
  .pipe(csv.parse({ headers: false }))
  .on("error", (error) => console.error(error))
  .on("data", (row) => console.log(`${computeScore(row[0])},${row[0]}`))
  .on("end", (rowCount: number) => console.log(`Parsed ${rowCount} rows`));

top10.csv