Difference between revisions of "Euler problems/161 to 170"
Jump to navigation
Jump to search
(Added problems 164-167) |
(Added problem_164) |
||
Line 28: | Line 28: | ||
Solution: |
Solution: |
||
<haskell> |
<haskell> |
||
+ | addDigit x = [[sum [x !! b !! c | c <- [0..9-a-b]] | b <- [0..9-a]] | a<-[0..9]] |
||
− | problem_164 = undefined |
||
+ | x3 = [[10-a-b | b <- [0..9-a]] | a <- [0..9]] |
||
+ | x20 = iterate addDigit x3 !! 17 |
||
+ | problem_164 = sum [x20 !! a !! b | a <- [1..9], b <- [0..9-a]] |
||
</haskell> |
</haskell> |
||
Revision as of 23:57, 10 November 2007
Problem 161
Triominoes
Solution:
problem_161 = undefined
Problem 162
Hexadecimal numbers
Solution:
problem_162 = undefined
Problem 163
Cross-hatched triangles
Solution:
problem_163 = undefined
Problem 164
Numbers for which no three consecutive digits have a sum greater than a given value.
Solution:
addDigit x = [[sum [x !! b !! c | c <- [0..9-a-b]] | b <- [0..9-a]] | a<-[0..9]]
x3 = [[10-a-b | b <- [0..9-a]] | a <- [0..9]]
x20 = iterate addDigit x3 !! 17
problem_164 = sum [x20 !! a !! b | a <- [1..9], b <- [0..9-a]]
Problem 165
Intersections
Solution:
problem_165 = undefined
Problem 166
Criss Cross
Solution:
problem_166 = undefined
Problem 167
Investigating Ulam sequences
Solution:
problem_167 = undefined