EN
TypeScript - Fibonacci sequence / number
3 points
Fibonacci numbers can be computed in three ways:
- with an iterative algorithm,
- with a recursive algorithm,
- with Binet's formula.
Note: presented implementations calculate Fibonacci numbers from 0.
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const calculateValue = (number: number): number => {2
if (number < 1) {3
return 0;4
}5
let a = 0;6
let b = 1;7
for (let i = 1; i < number; ++i) {8
const c = a + b;9
a = b;10
b = c;11
}12
return b;13
};14
15
16
// Usage example:17
18
for (let n = 0; n < 10; ++n) {19
const value = calculateValue(n);20
console.log('f(' + n + ')=' + value);21
}Output:
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f(0)=02
f(1)=13
f(2)=14
f(3)=25
f(4)=36
f(5)=57
f(6)=88
f(7)=139
f(8)=2110
f(9)=34
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const calculateValue = (input: number): number => {2
if (input < 1) return 0;3
if (input < 2) return 1;4
return calculateValue(input - 2) + calculateValue(input - 1);5
};6
7
8
// Usage example:9
10
for (let n = 0; n < 10; ++n) {11
const value = calculateValue(n);12
console.log('f(' + n + ')=' + value);13
}Output:
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f(0)=02
f(1)=13
f(2)=14
f(3)=25
f(4)=36
f(5)=57
f(6)=88
f(7)=139
f(8)=2110
f(9)=34
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const calculateValue = (input: number): number => {2
const a = Math.pow(1 + 2.23606797749979, input);3
const b = Math.pow(1 - 2.23606797749979, input);4
const c = 2.23606797749979 * Math.pow(2, input);5
return Math.round((a - b) / c);6
};7
8
9
// Usage example:10
11
for (let n = 0; n < 10; ++n) {12
const value = calculateValue(n);13
console.log('f(' + n + ')=' + value);14
}Output:
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f(0)=02
f(1)=13
f(2)=14
f(3)=25
f(4)=36
f(5)=57
f(6)=88
f(7)=139
f(8)=2110
f(9)=34
