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@Arlorean
Created January 10, 2020 16:28
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using System;
using number = System.Decimal;
namespace Fibonacci {
class Program {
// Recursion
static number fibr(number n) {
if (n == 0) { return 0; }
if (n == 1) { return 1; }
return fibr(n - 1) + fibr(n - 2);
}
// Tail Recursion
static number fibtr(number n, number a, number b) {
if (n == 0) { return a; }
if (n == 1) { return b; }
return fibtr(n-1, b, a+b);
}
// Iteration
static number fibi(number n) {
if (n == 0) { return 0; }
if (n == 1) { return 1; }
number a = 0, b = 1;
for (var i=2; i <= n; ++i) {
var c = a + b;
a = b;
b = c;
}
return b;
}
static void Main(string[] args) {
for (var i=0; i < 100; i++) {
Console.WriteLine($"fibtr({i}) = {fibtr(i, 0, 1)}, fibi({i}) = {fibi(i)}");
}
}
}
}
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