Get planet to destroy to make even and odd sums of planet mass same

planet-mass-stable.ts

'use strict';

const fs = require('fs');

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

let inputString = '';
let currentLine = 0;

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

process.stdin.on('end', function() {
  inputString = inputString.split('\n');

  main();
});

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

/*
 * Complete the 'getPlanetToDestroy' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts INTEGER_ARRAY planets as parameter.
 */

function getPlanetToDestroy(planets) {
  const numberIndexHashmap = {};
  const planetsMassSum = {
    even: 0,
    odd: 0
  };
  const oddNumbersSet = [];
  planets.forEach((planetMass, index) => {
    if (!numberIndexHashmap[planetMass]) {
      numberIndexHashmap[planetMass] = index;
    }
    planetsMassSum[index % 2 === 0 ? 'even' : 'odd'] += planetMass;
    if (planetMass % 2 !== 0) {
      oddNumbersSet.push(planetMass);
    }
  });

  let planetsMassSumTotal = planetsMassSum.even + planetsMassSum.odd;
  console.log({
    planets,
    planetsMassSum,
    planetsMassSum,
    numberIndexHashmap,
    oddNumbersSet
  });

  for (let index = 0; index < oddNumbersSet.length; index++) {
    const oddNumber = oddNumbersSet[index];
    const planetsMassSumAfterOddNumDeds = planetsMassSumTotal - oddNumber;
    const isPlanetsMassSumEven = planetsMassSumAfterOddNumDeds % 2 === 0;
    console.log({
      oddNumber,
      planetsMassSumAfterOddNumDeds,
      isPlanetsMassSumEven
    });
    if (isPlanetsMassSumEven && numberIndexHashmap[oddNumber]) {
      return numberIndexHashmap[oddNumber] + 1;
    }
  }

  return -1;
}
function main() {
  const ws = fs.createWriteStream(process.env.OUTPUT_PATH);

  const planetsCount = parseInt(readLine().trim(), 10);

  let planets = [];

  for (let i = 0; i < planetsCount; i++) {
    const planetsItem = parseInt(readLine().trim(), 10);
    planets.push(planetsItem);
  }

  const result = getPlanetToDestroy(planets);

  ws.write(result + '\n');

  ws.end();
}

// [2, 5, 6, 7, 8, 4];