My name is Aaron Hsu, and I'm a computer scientist. I'm changing the way people look at computing and programming languages, what they can do with them, and how they do it.
I figure it's about time I posted another Project Euler.Problem #30: ∇Z←PETHIRTY;M [1] ⍝ Find the sum of all the numbers that can be written as [2] ⍝ the sum of fifth powers of their decimal digits. [3] Z←+/1↓((⍳M)=+⌿(((1+⌊10⍟M)⍴10)⊤⍳M)*5)
Problem #29:∇Z←PETWENTYNINE;⎕IO ⎕IO←1 ⍝ Compute the cardinality of the set ⍝ {a*b | 2≤a≤100 ^ 2≤b≤100} ⍝ Easy to do by computing the sequence, ⍝ ordering it, and then removing duplicates. Z←⍴(-1⌽1↓(Z≠-1⌽Z),1)/Z←Z[⍋Z←,(1↓⍳100)∘.*(1↓⍳100)] ∇Another easy
Problem #28:Z←PETWENTYEIGHT ⍝ Sum of the diagonals of a 1001 by 1001 spiral Z←+/+1,4/2×⍳500 This one is too easy to talk about. Basically, we can realize the nature of the spiral and the diagonals is easy to think about without generating the spiral.On the
Problem #27:∇Z←PETWENTYSEVEN;A;B;X;P ⍝ Find the product of the coefficients A and B ⍝ that have the longest consecutive n values from 0 ⍝ for the quadratic formula. ⍝ P is the prime table used by CONS∆PRMS. ⍝ Seed it with the primes we use for B since we
Problem #26:∇Z←CYCLE∆LENGTH N;A;I;R ⍝ Find the length of the cycle of 1÷N. Z←0 ⋄ I←0 ⋄ A←N⍴0 ⋄ R←1 LP:I←I+1 ⋄ Z←I-A[R] ⋄ →(0≠A[R])/0 A[R]←I ⋄ R←N|R×10 ⋄ →(0=R)/Z←0 →LP