73 lines
2.3 KiB
Python
73 lines
2.3 KiB
Python
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import math
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def inputTypeCheck(message, type, errorMessage):
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while True:
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inputValue = input(message)
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try:
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return type(inputValue)
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except ValueError:
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print(errorMessage)
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def removeEmptyDecimals(number):
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hasEmptyDecimals = (number == int(number))
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return int(number) if hasEmptyDecimals else number
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def myRoundFunction(integerPart,decimalPart,amountOfDecimals):
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decimalOffset = len(str(integerPart))
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roundOffset = decimalOffset + amountOfDecimals
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numberString = f'{integerPart}{decimalPart}'
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lastDigit = int(numberString[roundOffset-1])
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firstEvalDigit = int(numberString[roundOffset])
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addPointAtOffset = lambda num,off: float(str(num)[:off] + '.' + str(num)[off:])
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if (firstEvalDigit < 5):
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return addPointAtOffset(numberString[:roundOffset], decimalOffset)
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elif (firstEvalDigit == 5):
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try:
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hasDigitsBehind5 = (int(numberString[roundOffset+1:]) > 0)
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except ValueError:
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hasDigitsBehind5 = False
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# This is the special case where round() rounds 2.5 down to 2.
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# It is only valid when there's no digits behind the eval digit
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# and when the base digit is even.
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specialCase = ((not hasDigitsBehind5) and (lastDigit % 2 == 0))
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roundedNumber = int(numberString[:roundOffset]) + 1 - specialCase
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return addPointAtOffset(roundedNumber, decimalOffset)
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else:
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return addPointAtOffset(int(numberString[:roundOffset]) + 1, decimalOffset)
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def main():
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integerPart = inputTypeCheck(
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message='Oppgi heltallsdelen av tallet (det foran punktum): ',
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type=int,
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errorMessage='Beklager, det du skrev inn er ikke et heltall. Prøv igjen\n'
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)
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decimalPart = inputTypeCheck(
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message='Oppgi desimaldelen av tallet (det bak punktum): ',
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type=int,
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errorMessage='Beklager, dette er ikke et tall, eller inneholder et desimalpunkt. Prøv igjen\n'
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)
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amountOfDecimals = inputTypeCheck(
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message='Oppgi ønsket antall desimaler i avrunding: ',
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type=int,
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errorMessage='Beklager, det du skrev inn er ikke et heltall. Prøv igjen\n'
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)
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roundedNumber = removeEmptyDecimals(myRoundFunction(integerPart, decimalPart, amountOfDecimals))
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print(f'{integerPart}.{decimalPart} avrundet til {amountOfDecimals} desimaler blir {roundedNumber}')
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def test():
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print(myRoundFunction(2, 5, 0))
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print(myRoundFunction(2, 15, 1))
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print(myRoundFunction(2, 500000000000000000001, 0))
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main()
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