Factorial: Difference between revisions
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z=n*factorial(n-1) |
z=n*factorial(n-1) |
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return z |
return z |
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</python> |
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=={{header|ALGOL 68}}== |
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===Iterative=== |
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PROC factorial = (INT in n)LONG LONG INT:( |
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INT n := in n; |
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LONG LONG INT z := n; |
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WHILE n>1 DO |
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n -:= 1; |
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z *:= n |
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OD; |
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z |
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); ~ |
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===Recursive=== |
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PROC factorial = (INT n)LONG LONG INT:( |
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IF n>1 THEN |
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n*factorial(n-1) |
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ELSE |
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1 |
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FI |
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); ~ |
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Revision as of 03:08, 17 August 2008
You are encouraged to solve this task according to the task description, using any language you may know.
The Factorial Function is the product of a sequence n, n-1, n-2...1 starting at the input number to the function.
Write a function to factorialise a number. Solutions can be iterative or recursive (though recursive solutions are generally considered too slow and are mostly used as an exercise in recursion). Support for negative n errors is optional.
References
Python
Iterative
<python>def factorial(n):
z=n
while n>1:
n=n-1
z=z*n
return z
</python>
Recursive
<python>def factorial(n):
z=1
if n>1:
z=n*factorial(n-1)
return z
</python>
ALGOL 68
Iterative
PROC factorial = (INT in n)LONG LONG INT:(
INT n := in n;
LONG LONG INT z := n;
WHILE n>1 DO
n -:= 1;
z *:= n
OD;
z
); ~
Recursive
PROC factorial = (INT n)LONG LONG INT:(
IF n>1 THEN
n*factorial(n-1)
ELSE
1
FI
); ~