Euler problems/71 to 80
From HaskellWiki
Contents |
1 Problem 71
Listing reduced proper fractions in ascending order of size.
Solution:
problem_71 = undefined
2 Problem 72
How many elements would be contained in the set of reduced proper fractions for d ≤ 1,000,000?
Solution:
problem_72 = undefined
3 Problem 73
How many fractions lie between 1/3 and 1/2 in a sorted set of reduced proper fractions?
Solution:
problem_73 = undefined
4 Problem 74
Determine the number of factorial chains that contain exactly sixty non-repeating terms.
Solution:
problem_74 = undefined
5 Problem 75
Find the number of different lengths of wire can that can form a right angle triangle in only one way.
Solution: This is only slightly harder than problem 39. The search condition is simpler but the search space is larger.
problem_75 = length . filter ((== 1) . length) $ group perims where perims = sort [scale*p | p <- pTriples, scale <- [1..10^6 `div` p]] pTriples = [p | n <- [1..1000], m <- [n+1..1000], even n || even m, gcd n m == 1, let a = m^2 - n^2, let b = 2*m*n, let c = m^2 + n^2, let p = a + b + c, p <= 10^6]
6 Problem 76
How many different ways can one hundred be written as a sum of at least two positive integers?
Solution:
problem_76 = undefined
7 Problem 77
What is the first value which can be written as the sum of primes in over five thousand different ways?
Solution:
problem_77 = undefined
8 Problem 78
Investigating the number of ways in which coins can be separated into piles.
Solution:
problem_78 = undefined
9 Problem 79
By analysing a user's login attempts, can you determine the secret numeric passcode?
Solution:
problem_79 = undefined
10 Problem 80
Calculating the digital sum of the decimal digits of irrational square roots.
Solution:
problem_80 = undefined
