[W6D5] (ArndtED) Adds js practice script

013849cd · earndt · 19806621 · 013849cd
Commit 013849cd authored Apr 09, 2021 by earndt
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demo.html demo.html +126 -0

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--- a/demo.html
+++ b/demo.html
+<!-- What is the index of the first Fibonacci number with 1000 digits? -->
+
+<html>
+	<head>
+		<title> Eric's awesome Demo </title>
+			<script type="text/javascript">
+				
+				const getNumMaxDigitPosition = (num) => Math.floor(Math.log10(num))
+
+const getNumAtDigitPosition = (num, digitPosition) =>
+	Math.floor(
+		(num % Math.pow(10, digitPosition + 1)) / Math.pow(10, digitPosition)
+	)
+
+const generateNaturalNumberObject = (num) => {
+	const finalObj = {}
+	const numMaxDigitPosition = getNumMaxDigitPosition(num)
+	for (
+		let digitPosition = 0;
+		digitPosition <= numMaxDigitPosition;
+		digitPosition++
+	) {
+		finalObj[digitPosition] = getNumAtDigitPosition(num, digitPosition)
+	}
+	return finalObj
+}
+
+const multiplyNumberObjectByValue = (numObj, natValue) => {
+	for (let digitPosition in numObj) {
+		multiplyNumObjValueAtDigitPositionAndNatValue(
+			numObj,
+			digitPosition,
+			natValue
+		)
+	}
+}
+
+const eliminateValueAtNumMaxDigit = (num, numMaxDigitPosition) =>
+	num % Math.pow(10, numMaxDigitPosition)
+
+const redistributeValuesOfNumObjectToCorrectPlaceIndices = (
+	numObj,
+	digitPosition
+) => {
+	while (numObj[digitPosition] > 9) {
+		const presentValue = numObj[digitPosition]
+		const presentValueMaxDigitPosition = getNumMaxDigitPosition(presentValue)
+		const numObjIdxToBeModified =
+			parseInt(digitPosition) + presentValueMaxDigitPosition
+		const valueToAddToNumObjAtTargetIdx = getNumAtDigitPosition(
+			presentValue,
+			presentValueMaxDigitPosition
+		)
+		const currentValueAtTargetIdx = numObj[numObjIdxToBeModified]
+		numObj[numObjIdxToBeModified] = currentValueAtTargetIdx
+			? currentValueAtTargetIdx + valueToAddToNumObjAtTargetIdx
+			: valueToAddToNumObjAtTargetIdx
+		numObj[digitPosition] = eliminateValueAtNumMaxDigit(
+			presentValue,
+			presentValueMaxDigitPosition
+		)
+	}
+}
+
+const numberObjectCorrectlyFormatted = (numObj) => {
+	for (let value of Object.values(numObj)) {
+		if (value < 0 || 9 < value) return false
+	}
+	return true
+}
+
+const ensureNumberObjectCorrectlyFormatted = (numObj) => {
+	while (!numberObjectCorrectlyFormatted(numObj)) {
+		for (let digitPosition in numObj) {
+			redistributeValuesOfNumObjectToCorrectPlaceIndices(
+				numObj,
+				digitPosition
+			)
+		}
+	}
+}
+
+const calculateSumOfTwoNumberObjects = (smllrNumObj, lrgrNumObj) => {
+	const sumNumObj = generateNaturalNumberObject(0)
+	for (let digitPosition in lrgrNumObj) {
+		sumNumObj[digitPosition] = smllrNumObj[digitPosition]
+			? smllrNumObj[digitPosition] + lrgrNumObj[digitPosition]
+			: lrgrNumObj[digitPosition]
+	}
+	ensureNumberObjectCorrectlyFormatted(sumNumObj)
+	return sumNumObj
+}
+
+function calculateIndexOfFirstFibonacciTermWithNumDigits(num) {
+	if (num < 0) return undefined
+	if (num < 2) return 1
+	let previousNumObj = generateNaturalNumberObject(1)
+	let currentNumObj = generateNaturalNumberObject(1)
+	let nextNumObj = generateNaturalNumberObject(2)
+	let idx = 3
+	let digitCount = 1
+	while (digitCount < num - 1) {
+		const newNextNumObj = calculateSumOfTwoNumberObjects(
+			currentNumObj,
+			nextNumObj
+		)
+		previousNumObj = currentNumObj
+		currentNumObj = nextNumObj
+		nextNumObj = newNextNumObj
+		digitCount = Math.max(
+			...Object.keys(nextNumObj).map((numStr) => parseInt(numStr))
+		)
+		idx++
+	}
+	return idx
+}
+			</script>
+	</head>
+
+	<body>
+		<script>
+			document.write("What is the index of the first Fibonacci number with 1000 digits? ")
+			document.write(calculateIndexOfFirstFibonacciTermWithNumDigits(1000))
+		</script>
+	</body>
+</html>
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