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Great Ideas in Computing Problem mapping. Richard Anderson University of Washington. Great Ideas in Computing. Great ideas in computing. What are the underlying ideas of our field Ideas that provide a deep understanding Ideas that give computer scientists intuition
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Great Ideas in ComputingProblem mapping Richard Anderson University of Washington IUCEE: Problem Mapping
Great Ideas in Computing IUCEE: Problem Mapping
Great ideas in computing • What are the underlying ideas of our field • Ideas that provide a deep understanding • Ideas that give computer scientists intuition • Ideas that create excitement? IUCEE: Problem Mapping
Four lectures • Monday – Problem Mapping • Tuesday – Complexity Theory • Wednesday – Average Case Analysis • Thursday – Algorithm Implementation • Convey ideas of theoretical computer science that span disciplines • Long term impact on students is the ideas they internalize • What they remember after they have forgotten the details! IUCEE: Problem Mapping
Mappings: Translations between different levels or domains D1 D2 IUCEE: Problem Mapping
Suppose you have a program to compute the maximum of an array of integers How do you compute the minimum? IUCEE: Problem Mapping
Suppose you have a program to sort positive integers How do you sort arbitrary integers? What is the mapping between problems? How is the mapping used? IUCEE: Problem Mapping
Two well know problems • Traveling Salesman Problem (TSP) • Hamiltonian Circuit Problem (HC) IUCEE: Problem Mapping
Does there exist a Hamiltonian Circuit in this graph? IUCEE: Problem Mapping
Find a minimum cost tour 3 7 7 2 2 5 4 1 1 4 IUCEE: Problem Mapping
How do you map a HC problem into a TSP problem • Imprecise version: • Precise version IUCEE: Problem Mapping
HC to TSP IUCEE: Problem Mapping
Undirected vs. Directed • Hamiltonian Circuit (HC) • Directed Hamiltonian Circuit (DHC) • Traveling Salesman Problem (STSP) • Asymmetric Traveling Salesman Problem (ATSP) IUCEE: Problem Mapping
HC to DHC IUCEE: Problem Mapping
DHC to HC IUCEE: Problem Mapping
TSP to ATSP / ATSP to TSP IUCEE: Problem Mapping
Job shop scheduling • Jobs j1… jn • Single machine • Time to execute job ji is ti • Time to convert from job ji to jk is cik • Cost to start with job ji is c0i • Cost to end with job ji is ci0 IUCEE: Problem Mapping
How is job shop scheduling related to the TSP IUCEE: Problem Mapping
Hamiltonian Path IUCEE: Problem Mapping