Lecture 6 — Algorithms: easy versus hard Tue 20 Oct 2026 · Alessandro Favero Slides Notes Self-test Recording Content Euler and the bridges of Königsberg From a city to a graph Euler's insight Scaling up: Venice Hamilton's icosian game Problems, algorithms and running time Problems and instances Algorithms Running time and the worst case Models of computation Scaling Kepler's third law Asymptotic notation An algorithm we can count: direct-summation gravity The importance of being polynomial Binary search The guessing game Searching a sorted array Running time A lower bound How hard can it get? Exercises