Created
September 8, 2024 16:13
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| /** | |
| * @param {number} num | |
| * @returns {string} | |
| */ | |
| function formatMoney(num) { | |
| return `R$ ${num | |
| .toFixed(2) | |
| .replace('.', ',') | |
| .replace(/(\d)(?=(\d\d\d)+(?!\d))/g, '$1.')}`; | |
| } | |
| function formatInteresPercentage(num) { | |
| return (num * 100).toFixed(2) + '%'; | |
| } | |
| function deductIR(investimentReturn, totalDaysInvested) { | |
| if (totalDaysInvested < 0) { | |
| return investimentReturn; | |
| } | |
| const [_, __, interestPercentage] = [ | |
| [0, 180, 0.225], | |
| [181, 360, 0.2], | |
| [361, 720, 0.175], | |
| [721, Infinity, 0.15], | |
| ].find(([min, max]) => min <= totalDaysInvested && totalDaysInvested <= max); | |
| return investimentReturn * (1 - interestPercentage); | |
| } | |
| function leaveMoneyInvestedAndPayInstallments( | |
| totalAmount, | |
| totalInstallments, | |
| annualInterestPercentage, | |
| ) { | |
| const installmentAmount = totalAmount / totalInstallments; | |
| let currentTotalAmount = totalAmount; | |
| console.log( | |
| `Investing ${formatMoney(totalAmount)} for ${ | |
| totalInstallments - 1 | |
| } months at ${formatInteresPercentage(annualInterestPercentage)}/year`, | |
| ); | |
| for ( | |
| let currentInstallmentNumber = 1; | |
| currentInstallmentNumber <= totalInstallments; | |
| currentInstallmentNumber++ | |
| ) { | |
| const monthlyInterestPercentage = Math.pow(annualInterestPercentage + 1, 1 / 12) - 1; | |
| const currentInvestimentReturn = currentTotalAmount * monthlyInterestPercentage; | |
| const actualCurrentInvestimentReturn = deductIR( | |
| currentInvestimentReturn, | |
| currentInstallmentNumber * 30, | |
| ); | |
| let text = `\n\n${currentInstallmentNumber}/${totalInstallments}\n${formatMoney( | |
| currentTotalAmount, | |
| )} - ${formatMoney(installmentAmount)} + ${formatMoney( | |
| actualCurrentInvestimentReturn, | |
| )} (${formatInteresPercentage(monthlyInterestPercentage)}/month)`; | |
| currentTotalAmount -= installmentAmount; | |
| currentTotalAmount += actualCurrentInvestimentReturn; | |
| text += ` = ${formatMoney(currentTotalAmount)}`; | |
| console.log(text); | |
| } | |
| return currentTotalAmount; | |
| } | |
| /** | |
| * console.log(formatMoney(leaveMoneyInvestedAndPayInstallments(10000.0, 10, 0.105))); | |
| * | |
| * 1/10 | |
| * R$ 10.000,00 - R$ 1.000,00 + R$ 64,75 (0.84%/month) = R$ 9.064,75 | |
| * | |
| * | |
| * 2/10 | |
| * R$ 9.064,75 - R$ 1.000,00 + R$ 58,70 (0.84%/month) = R$ 8.123,45 | |
| * | |
| * | |
| * 3/10 | |
| * R$ 8.123,45 - R$ 1.000,00 + R$ 52,60 (0.84%/month) = R$ 7.176,05 | |
| * | |
| * | |
| * 4/10 | |
| * R$ 7.176,05 - R$ 1.000,00 + R$ 46,47 (0.84%/month) = R$ 6.222,52 | |
| * | |
| * | |
| * 5/10 | |
| * R$ 6.222,52 - R$ 1.000,00 + R$ 40,29 (0.84%/month) = R$ 5.262,81 | |
| * | |
| * | |
| * 6/10 | |
| * R$ 5.262,81 - R$ 1.000,00 + R$ 34,08 (0.84%/month) = R$ 4.296,89 | |
| * | |
| * | |
| * 7/10 | |
| * R$ 4.296,89 - R$ 1.000,00 + R$ 28,72 (0.84%/month) = R$ 3.325,61 | |
| * | |
| * | |
| * 8/10 | |
| * R$ 3.325,61 - R$ 1.000,00 + R$ 22,23 (0.84%/month) = R$ 2.347,84 | |
| * | |
| * | |
| * 9/10 | |
| * R$ 2.347,84 - R$ 1.000,00 + R$ 15,69 (0.84%/month) = R$ 1.363,53 | |
| * | |
| * | |
| * 10/10 | |
| * R$ 1.363,53 - R$ 1.000,00 + R$ 9,11 (0.84%/month) = R$ 372,64 | |
| * R$ 372,64 | |
| */ |
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