martinr448
martinr448
/ SecureCoding.swift
Created
September 30, 2018 19:21
https://stackoverflow.com/q/52544461/1187415
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| import Foundation | |
| @objcMembers class ClassA: NSObject, NSSecureCoding { | |
| var title: String | |
| init(title: String) { | |
| self.title = title | |
| } | |
| func encode(with aCoder: NSCoder) { |
martinr448
/ prodsum.py
Last active
September 4, 2018 18:23
https://codereview.stackexchange.com/q/203109/35991
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| def sum_of_products(a, n): | |
| running_totals = [0] * n | |
| for x in a: | |
| for i in range(n - 1): | |
| running_totals[i] += running_totals[i + 1] * x | |
| running_totals[-1] += x | |
| return running_totals[0] |
martinr448
/ permutations.swift
Last active
September 4, 2018 09:20
https://stackoverflow.com/a/52136303/1187415
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| import Foundation | |
| func permute<E>(i: Int, array: [E]) -> [E] { | |
| var i = i | |
| var result = array | |
| for j in 0..<array.count { | |
| let k = i % (array.count - j) | |
| i /= (array.count - j) | |
| result.swapAt(j, j + k) | |
| } |
martinr448
/ permutations.py
Last active
August 16, 2018 19:27
https://codereview.stackexchange.com/a/201749/35991
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| def from_permutation_to_disjoints_cycles(perm): | |
| mappings = { a: b for a, b in zip(*perm) } | |
| cycles = [] | |
| for a in perm[0]: | |
| b = mappings.pop(a, None) | |
| if b is None: | |
| continue # `a` has already been handled | |
| cycle = [a] | |
| while a != b: | |
| cycle.append(b) |