Sparse Arrays Hacker Rank

matchingStrings.js

'use strict';

const fs = require('fs');

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', _ => {
    inputString = inputString.replace(/\s*$/, '')
        .split('\n')
        .map(str => str.replace(/\s*$/, ''));

    main();
});

function readLine() {
    return inputString[currentLine++];
}

// Complete the matchingStrings function below.
function matchingStrings(strings, queries) {

    const hasTable = strings.reduce((memo, value) => (memo[value] ? memo[value]++ : memo[value] = 1, memo)
        , {})
    return queries.map((value) => hasTable[value] || 0)

}

function main() {
    const ws = fs.createWriteStream(process.env.OUTPUT_PATH);

    const stringsCount = parseInt(readLine(), 10);

    let strings = [];

    for (let i = 0; i < stringsCount; i++) {
        const stringsItem = readLine();
        strings.push(stringsItem);
    }

    const queriesCount = parseInt(readLine(), 10);

    let queries = [];

    for (let i = 0; i < queriesCount; i++) {
        const queriesItem = readLine();
        queries.push(queriesItem);
    }

    let res = matchingStrings(strings, queries);

    ws.write(res.join("\n") + "\n");

    ws.end();
}