Difference between revisions of "Euler problems/171 to 180"
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(add problem 175) |
Marypoppins (talk | contribs) |
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| + | Do them on your own! |
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| − | == [http://projecteuler.net/index.php?section=problems&id=171 Problem 171] == |
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| − | Finding numbers for which the sum of the squares of the digits is a square. |
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| − | |||
| − | Solution: |
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| − | <haskell> |
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| − | problem_171 = undefined |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=172 Problem 172] == |
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| − | Investigating numbers with few repeated digits. |
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| − | |||
| − | Solution: |
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| − | <haskell> |
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| − | problem_172 = undefined |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=173 Problem 173] == |
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| − | Using up to one million tiles how many different "hollow" square laminae can be formed? |
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| − | Solution: |
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| − | <haskell> |
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| − | problem_173= |
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| − | let c=div (10^6) 4 |
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| − | xm=floor$sqrt $fromIntegral c |
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| − | k=[div c x|x<-[1..xm]] |
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| − | in sum k-(div (xm*(xm+1)) 2) |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=174 Problem 174] == |
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| − | Counting the number of "hollow" square laminae that can form one, two, three, ... distinct arrangements. |
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| − | |||
| − | Solution: |
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| − | <haskell> |
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| − | problem_174 = undefined |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=175 Problem 175] == |
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| − | Fractions involving the number of different ways a number can be expressed as a sum of powers of 2. |
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| − | Solution: |
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| − | <haskell> |
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| − | sternTree x 0=[] |
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| − | sternTree x y= |
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| − | m:sternTree y n |
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| − | where |
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| − | (m,n)=divMod x y |
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| − | findRat x y |
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| − | |odd l=take (l-1) k++[last k-1,1] |
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| − | |otherwise=k |
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| − | where |
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| − | k=sternTree x y |
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| − | l=length k |
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| − | p175 x y= |
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| − | init$foldl (++) "" [a++","| |
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| − | a<-map show $reverse $filter (/=0)$findRat x y] |
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| − | problems_175=p175 123456789 987654321 |
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| − | test=p175 13 17 |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=176 Problem 176] == |
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| − | Rectangular triangles that share a cathetus. |
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| − | Solution: |
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| − | <haskell> |
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| − | problem_176 = undefined |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=177 Problem 177] == |
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| − | Integer angled Quadrilaterals. |
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| − | |||
| − | Solution: |
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| − | <haskell> |
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| − | problem_177 = undefined |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=178 Problem 178] == |
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| − | Step Numbers |
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| − | Solution: |
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| − | <haskell> |
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| − | problem_178 = undefined |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=179 Problem 179] == |
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| − | Consecutive positive divisors. |
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| − | Solution: |
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| − | <haskell> |
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| − | problem_179 = undefined |
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| − | </haskell> |
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| − | |||
| − | == [http://projecteuler.net/index.php?section=problems&id=180 Problem 180] == |
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| − | |||
| − | Solution: |
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| − | <haskell> |
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| − | problem_180 = undefined |
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| − | </haskell> |
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Revision as of 21:42, 29 January 2008
Do them on your own!