2021-11-20 16:21:25 +05:30
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/**
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2022-02-22 16:50:46 +06:00
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* @function fibonacci
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2021-11-20 16:21:25 +05:30
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* @description Fibonacci is the sum of previous two fibonacci numbers.
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* @param {Integer} N - The input integer
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* @return {Integer} fibonacci of N.
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* @see [Fibonacci_Numbers](https://en.wikipedia.org/wiki/Fibonacci_number)
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*/
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2020-10-05 23:43:03 +05:30
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const fibonacci = (N) => {
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2022-02-22 16:50:46 +06:00
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if (!Number.isInteger(N)) {
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throw new TypeError('Input should be integer')
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2020-10-05 23:43:03 +05:30
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}
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2022-02-22 16:50:46 +06:00
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// memoize the last two numbers
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let firstNumber = 0
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let secondNumber = 1
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for (let i = 1; i < N; i++) {
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const sumOfNumbers = firstNumber + secondNumber
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// update last two numbers
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firstNumber = secondNumber
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secondNumber = sumOfNumbers
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}
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return N ? secondNumber : firstNumber
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2020-10-05 23:43:03 +05:30
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}
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2021-10-10 17:00:21 +02:00
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export { fibonacci }
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