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| − | [http://conservapedia.com/Recursion Recursion]<ref>[http://conservapedia.com/Recursion See http://conservapedia.com/Recursion]</ref><ref>[http://conservapedia.com/Recursion See http://conservapedia.com/Recursion]</ref><ref>[http://conservapedia.com/Recursion See http://conservapedia.com/Recursion]</ref><ref>[http://conservapedia.com/Recursion See http://conservapedia.com/Recursion]</ref><ref>[http://conservapedia.com/Recursion See http://conservapedia.com/Recursion]</ref><ref>[http://conservapedia.com/Recursion See http://conservapedia.com/Recursion]</ref><ref>[http://conservapedia.com/Recursion See http://conservapedia.com/Recursion]</ref> is a technique whereby a [[function]], in order to accomplish a task, calls [http://conservapedia.com/Recursion itself] to accomplish part of the task. [http://conservapedia.com/Recursion Recursion] is notable for having the word "[http://conservapedia.com/Recursion recursion]" in itself.
| + | '''Recursion''' is the repeated application of a procedure or definition through reference to itself. |
| | + | |
| | + | ==In Mathematics== |
| | + | |
| | + | There's a simple procedure for finding out whether a number is divisible by three. |
| | + | #If the number is 3, 6, or 9 then it's divisible by three. |
| | + | #Otherwise, add all the digits of the number; if the sum of the digits is divisible by three, then so is the original number. |
| | + | |
| | + | Examples: |
| | + | * 12 => 1 + 2 = 3 (yes) |
| | + | * 14 => 1 + 4 = 5 (no) |
| | + | * 96 => 9 + 6 = 15; 15 => 1 + 5 = 6 |
| | + | |
| | + | |
| | + | ==In Computing== |
| | + | |
| | + | Recursion is a technique whereby a [[function]], in order to accomplish a task, calls itself to accomplish part of the task. |
| | | | |
| | Every recursive solution involves two major parts or cases, the second part having three components: | | Every recursive solution involves two major parts or cases, the second part having three components: |
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| | * recursive case(s). A recursive case has three components: | | * recursive case(s). A recursive case has three components: |
| | ::1. divide the problem into one or more simpler or smaller parts of the problem, | | ::1. divide the problem into one or more simpler or smaller parts of the problem, |
| − | ::2. call the function [http://conservapedia.com/Recursion (recursively)] on each part, and | + | ::2. call the function (recursively) on each part, and |
| | ::3. combine the solutions of the parts into a solution for the problem. | | ::3. combine the solutions of the parts into a solution for the problem. |
| − | ::4. If that fails, [http://conservapedia.com/Recursion this] article provides more information on [http://conservapedia.com/Recursion recursion]
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| | | | |
| | These exercises are useful to see examples of recursion: | | These exercises are useful to see examples of recursion: |
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| | :1. Write a function to compute the sum of all numbers from 1 to n. | | :1. Write a function to compute the sum of all numbers from 1 to n. |
| | :2. Write a function to compute 2 to the power of a non-negative integer. | | :2. Write a function to compute 2 to the power of a non-negative integer. |
| − | :3. Write a function to compute any number to the power of a non-negative integer. | + | :3. Write a function to compute any number to the power of a non-negative integer. |
| − | :4. Write an article about [http://conservapedia.com/Recursion recursion]; attempt to reference the article in itself as many times as possible <ref> Like I'm doing now, also see http://conservapedia.com/Recursion</ref>
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| − | If you still don't understand, see [http://conservapedia.com/Recursion recursion]
| + | ==External links== |
| | + | * [http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00sc-introduction-to-computer-science-and-programming-spring-2011/unit-1/lecture-6-recursion/ Unit on recursion in free online computer science course from MIT.] |
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| | [[Category:Computer Science]] | | [[Category:Computer Science]] |
| − | | + | [[Category:Mathematics]] |
| − | | |
| − | ===References===
| |
| − | <references/>
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