CS252 Algorithms
Monday, 3 October 2022

+ Office hours today canceled
- I'll try to schedule a couple extra hours this week

+ Questions
- Diameter
- other?

+ Interval scheduling
- Example: what if we greedily choose earliest start time?
- Example: what if we greedily choose shortest interval?

+ Dijkstra's Algorithm intro

+ Proof-writing
- Some principles
    - Seek clarity, correctness, persuasiveness
    - Name things
    - Embrace mathematical notation--it's designed for this!
    - Outline, write, evaluate logical flow & clarity, rewrite

- Let's do P1.1
    - basic strategy
    - things to name
    - turn that naming into an algorithm
    - correctness proof
 




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C[k] = count k
S[-1] = 0
S[k] = Sum_j=0^k C[j]
R[m,n] = Sum_j=m^n C[j]
Claim: R[m,n] = S[m] - S[k]