Cycling & Cycle Touring

Combinatorial optimization problems arise across logistics, scheduling, and engineering, and C++ remains a language of choice when performance matters. This lecture takes a practical look at solving such problems in C++, using the Electric Vehicle Routing Problem as a running example. We begin with an exact solver, formulating the problem as a mixed-integer program and trying to solve it through GLPK's C API directly from C++. Exact methods, however, quickly hit their limits on real-world instances. The second half of the talk turns to metaheuristics: how they are designed, why C++ is particularly well suited for implementing them, and what design choices matter most in practice. We'll walk through a concrete implementation, touching on data structures for fast neighborhood evaluation, generic algorithm design with templates, and the performance considerations that separate a prototype from a production-ready solver. The goal is not to advocate for one approach over another, but to show how C++ supports the full spectrum of optimization techniques.

JOINING THE EVENT Please join the event through the Sketchy Collective international group. The Sarajevo sub-group is temporary and was created to make our group more visible to people in Sarajevo. You can find the link to the same event in the international group here: https://www.meetup.com/sketchy-collective-international/events/314735747/?eventOrigin=group_events_list HOW TO FIND US We’re meeting in the park around Liberation Square (Trg oslobođenja) on Thursday, 28.05, at 18:00 (no problem if you’re slightly late). Just look for the people with sketchbooks :) You can also follow us on Instagram - we’ll post some stories just before the meetup starts to help you locate us more easily in the park. \*\*\* HOW IT WORKS At each meetup, attendees take turns modeling for quick 10-minute sketch sessions. One person poses while everyone else sketches, then we rotate. \*\*\* WHAT TO BRING Pencils and paper (or any sketching tools you prefer). \*\*\* No fees, no pressure. The only thing we ask is that everyone takes a turn posing for the group. You can sit in whatever position feels comfortable - the 10 minutes go by quickly! Draw as much as you like, skip a round if you’re tired or just want to chat, and leave whenever it suits you. The event continues as long as there’s interest. \*\*\* STAYING CONNECTED We have a WhatsApp group for staying in touch and sharing updates. Ask the organizer to add you to the WhatsApp group during the meetup.

HOW TO FIND US We’re meeting in the park around Liberation Square (Trg oslobođenja) on Thursday, 28.05, at 18:00 (no problem if you’re slightly late). Just look for the people with sketchbooks :) You can also follow us on Instagram - we’ll post some stories just before the meetup starts to help you locate us more easily in the park. Please note that the event starts at 18:00 local Sarajevo time (GMT+2). Meetup.com may display an incorrect time because the international group’s location is set to Finland, which is in a different time zone. \*\*\* HOW IT WORKS At each meetup, attendees take turns modeling for quick 10-minute sketch sessions. One person poses while everyone else sketches, then we rotate. \*\*\* WHAT TO BRING Pencils and paper (or any sketching tools you prefer). \*\*\* No fees, no pressure. The only thing we ask is that everyone takes a turn posing for the group. You can sit in whatever position feels comfortable - the 10 minutes go by quickly! Draw as much as you like, skip a round if you’re tired or just want to chat, and leave whenever it suits you. The event continues as long as there’s interest. \*\*\* STAYING CONNECTED We have a WhatsApp group for staying in touch and sharing updates. Ask the organizer to add you to the WhatsApp group during the meetup.

Combinatorial optimization problems arise across logistics, scheduling, and engineering, and C++ remains a language of choice when performance matters. This lecture takes a practical look at solving such problems in C++, using the Electric Vehicle Routing Problem as a running example. We begin with an exact solver, formulating the problem as a mixed-integer program and trying to solve it through GLPK's C API directly from C++. Exact methods, however, quickly hit their limits on real-world instances. The second half of the talk turns to metaheuristics: how they are designed, why C++ is particularly well suited for implementing them, and what design choices matter most in practice. We'll walk through a concrete implementation, touching on data structures for fast neighborhood evaluation, generic algorithm design with templates, and the performance considerations that separate a prototype from a production-ready solver. The goal is not to advocate for one approach over another, but to show how C++ supports the full spectrum of optimization techniques.

Discover practical ways homeowners can expand tree canopy on their own properties and advocate for stronger tree coverage in their communities. Come learn how important trees are, even in our own yards, for helping with climate change by absorbing carbon and reducing heat, providing habitat for wildlife, and improving the health and wellbeing of our communities through cleaner air, shade, and more comfortable places to live. **Presenter** Todd Fleishans is a local consulting arborist with more than twenty years of experience. His credentials include ISA Board Certified Master Arborist, Certified Urban Forestry Arborist, Certified Tree Safety Professional, and Registered Consulting Arborist. He works with residential, commercial, and municipal clients, providing expertise in tree identification, health, risk assessment, and valuation. **Evening's Agenda** This meeting has the option to either attend in-person at the Bloomfield Township Library at 1099 Lone Pine Rd, Bloomfield Township, MI 48302 in Meeting Room 2 or online via Zoom. For those attending in-person, there will be a meet-n-greet before the presentation - see the agenda below for details. * 6:30 pm – Doors open for a meet and greet with members, supporters, and the local Sierra Club Executive Committee * 7:00 pm – Introductions and presentation begin (remote participants should join at this time) * 8:00 pm – Question-and-answer session begins **About SEMG Monthly Meetings & Presentations:** The Sierra Club Southeast Michigan Group (SEMG) offers free presentations during its monthly first-Thursday meetings at 7 pm. Meetings are held via Zoom or in person, begin with brief announcements, and feature an hour-long presentation with Q&A. All are welcome.

**Weather permitting**, we’ll take a casual ride from Pickerington Ponds (Glacier Knoll) to Three Creeks and back. Distance is **18–25 miles**, depending on where we turn around and whether we add a side loop. Pace is around **12 mph**, but this is a fun, no‑drop ride — we can slow down as needed. Here’s the **map** showing Glacier Knoll (bike), Confluence Park (flag), and BrewDog: [https://www.google.com/maps/d/edit..](https://www.google.com/maps/d/edit..). Text or call Scott at **614‑975‑4458** if you’re coming. Columbus ski club membership not required for this event. CSC assumes no responsibility for the event or any injuries as this is organized by a third party.

This is an all inclusive event to inform, support and help bring special needs families and the community together. Come and enjoy family and sensory friendly: games, activities, snacks, free stuff and more! Meets the 2nd Saturday of each month. Located at Village Chapel - 30 Circleville Avenue, Ashville, OH 43103.

**Weather permitting**, we’ll take a casual ride from Pickerington Ponds (Glacier Knoll) to Three Creeks and back. Distance is **18–25 miles**, depending on where we turn around and whether we add a side loop. Pace is around **12 mph**, but this is a fun, no‑drop ride — we can slow down as needed. Here’s the **map** showing Glacier Knoll (bike), Confluence Park (flag), and BrewDog: [https://www.google.com/maps/d/edit..](https://www.google.com/maps/d/edit..). Text or call Scott at **614‑975‑4458** if you’re coming. Columbus ski club membership not required for this event. CSC assumes no responsibility for the event or any injuries as this is organized by a third party.

BIKE RIDE TO SUNBURY Dust off your bikes, pump up your tires, and get out and ride. • When: Saturday, May 30, 10AM • Where: Leaving from the Westerville Library, 126 S. State Street, 43081 ◦ Meet at East side of parking lot by the playground. Trip Itentiary • 20 miles round trip • Ride to Sunbury, stop for lunch (Location TBD), then ride back to the Westerville Library • All skill levels welcome Contact: Therese Butz (614-561-1976), Art Kahn (614-370-5246) Columbus Ski Club membership not required for this event. CSC assumes no responsibility for the event or any injuries as this is organized by a third party.