Fibonacci without recursion added (#159)

* changes made

* Update Fibonacci.js

* fib

Co-authored-by: vinayak <itssvinayak@gmail.com>
This commit is contained in:
Satzyakiz
2020-05-09 10:06:07 +05:30
committed by GitHub
parent 8655fd0171
commit f4fdfd2b4b
2 changed files with 24 additions and 25 deletions

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@ -1,25 +0,0 @@
// Calculates fib(n) such that fib(n) = fib(n - 1) + fib(n - 2)
// fib(0) = fib(1) = 1
// Uses a bottom up dynamic programming approach
// Solve each subproblem once, using results of previous subproblems,
// which are n-1 and n-2 for Fibonacci numbers
// Although this algorithm is linear in space and time as a function
// of the input value n, it is exponential in the size of n as
// a function of the number of input bits
function fib (n) {
var table = []
table.push(1)
table.push(1)
for (var i = 2; i < n; ++i) {
table.push(table[i - 1] + table[i - 2])
}
console.log('Fibonacci #%d = %d', n, table[n - 1])
}
fib(1)
fib(2)
fib(200)
fib(5)
fib(10)

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@ -48,6 +48,27 @@ const FibonacciRecursiveDP = (stairs) => {
return res
}
// Algorithms
// Calculates Fibonacci(n) such that Fibonacci(n) = Fibonacci(n - 1) + Fibonacci(n - 2)
// Fibonacci(0) = Fibonacci(1) = 1
// Uses a bottom up dynamic programming approach
// Solve each sub-problem once, using results of previous sub-problems
// which are n-1 and n-2 for Fibonacci numbers
// Although this algorithm is linear in space and time as a function
// of the input value n, it is exponential in the size of n as
// a function of the number of input bits
// @Satzyakiz
const FibonacciDpWithoutRecursion = (number) => {
const table = []
table.push(1)
table.push(1)
for (var i = 2; i < number; ++i) {
table.push(table[i - 1] + table[i - 2])
}
return (table)
}
// testing
console.log(FibonacciIterative(5))
@ -57,3 +78,6 @@ console.log(FibonacciRecursive(5))
console.log(FibonacciRecursiveDP(5))
// Output: 5
console.log(FibonacciDpWithoutRecursion(5))
// Output: [ 1, 1, 2, 3, 5 ]