Getting started with C# Language Verbatim Strings Operators Extension Methods Collection Initializers String Interpolation C# 6.0 Features Constructors and Finalizers Keywords Generics Reflection Inheritance Null-Coalescing Operator Using Statement String Escape Sequences Exception Handling Null-conditional Operators Built-in Types Lambda expressions Async-Await Properties Threading Using Directive Methods Yield Keyword Events LINQ Queries Common String Operations Expression Trees Overload Resolution String.Format nameof Operator Unsafe Code in .NET Initializing Properties BindingList<T>ILGenerator Object initializers XML Documentation Comments Preprocessor directives Dynamic type Anonymous types Structs Tuples Enum Access Modifiers Task Parallel Library Attributes Guid Singleton Implementation Delegates Nullable types Garbage Collector in .Net Networking Arrays Equality Operator Lock Statement Action Filters XmlDocument and the System.Xml namespace DateTime Methods BackgroundWorker Polymorphism Static Classes Indexer IDisposable interface Aliases of built-in types Immutability XDocument and the System.Xml.Linq namespace C# 7.0 Features Performing HTTP requests Generating Random Numbers in C#Looping Named Arguments Diagnostics Interfaces IEnumerable Naming Conventions An overview of c# collections Checked and Unchecked Recursion Functional Programming Literals Casting NullReferenceException Func delegates LINQ to XML Hash Functions Handling FormatException when converting string to other types Cryptography (System.Security.Cryptography)INotifyPropertyChanged interface Value type vs Reference type C# 4.0 Features IQueryable interface Task Parallel Library (TPL) Dataflow Constructs Stream Runtime Compile Conditional Statements Interoperability Overflow Equals and GetHashCode Type Conversion Parallel LINQ (PLINQ)String Manipulation String Concatenate Partial class and methods Stopwatches Regex Parsing C# Script C# 3.0 Features Async/await, Backgroundworker, Task and Thread Examples Timers Function with multiple return values Binary Serialization Making a variable thread safe IComparable Code Contracts Iterators AssemblyInfo.cs Examples File and Stream I/O Code Contracts and Assertions Caching C# 5.0 Features Implementing Flyweight Design Pattern StringBuilder Implementing Decorator Design Pattern Accessing Databases T4 Code Generation Microsoft.Exchange.WebServices .NET Compiler Platform (Roslyn)Data Annotation Using SQLite in C#System.Management.Automation FileSystemWatcher System.DirectoryServices.Protocols.LdapConnection Named and Optional Arguments Comments and regions C# Authentication handler Pointers & Unsafe Code Pointers How to use C# Structs to create a Union type (Similar to C Unions)BigInteger Dependency Injection Reactive Extensions (Rx)Creational Design Patterns Creating a Console Application using a Plain-Text Editor and the C# Compiler (csc.exe)Reading and writing .zip files Generic Lambda Query Builder Import Google Contacts Lambda Expressions CLSCompliantAttribute ObservableCollection<T>Synchronization Context in Async-Await ICloneable Read & Understand Stacktraces Linq to Objects ASP.NET Identity Access network shared folder with username and password Asynchronous Socket Structural Design Patterns O(n) Algorithm for circular rotation of an array Creating Own MessageBox in Windows Form Application Including Font Resources Object Oriented Programming In C#Using json.net Getting Started: Json with C#Windows Communication Foundation

BigInteger

Remarks:

When To Use

BigInteger objects are by their very nature very heavy on RAM. Consequently, they should only be used when absolutely necessary, ie for numbers on a truly astronomical scale.

Further to this, all arithmetic operations on these objects are an order of magnitude slower than their primitive counterparts, this problem gets further compounded as the number grows as they are not of a fixed size. It is therefore feasibly possible for a rogue BigInteger to cause a crash by consuming all of the available RAM.

Alternatives

If speed is imperative to your solution it may be more efficient to implement this functionality yourself using a class wrapping a Byte[] and overloading the necessary operators yourself. However, this does require a significant amount of extra effort.

Calculate the First 1,000-Digit Fibonacci Number

Include using System.Numerics and add a reference to System.Numerics to the project.

using System;
using System.Numerics;

namespace Euler_25
{
    class Program
    {
        static void Main(string[] args)
        {
            BigInteger l1 = 1;
            BigInteger l2 = 1;
            BigInteger current = l1 + l2;
            while (current.ToString().Length < 1000)
            {
                l2 = l1;
                l1 = current;
                current = l1 + l2;
            }
            Console.WriteLine(current);
        }
    }
}

This simple algorithm iterates through Fibonacci numbers until it reaches one at least 1000 decimal digits in length, then prints it out. This value is significantly larger than even a ulong could hold.

Theoretically, the only limit on the BigInteger class is the amount of RAM your application can consume.

Note: BigInteger is only available in .NET 4.0 and higher.

Contributors

Topic Id: 5654

Example Ids: 20049

This site is not affiliated with any of the contributors.