2.1 引言 2.2 基本编码方法 2.3 图像编码标准 2.4 语音编码标准

Algorithms Day 40 L23.2 Recall from Lecture 22 • Flow value: | f | = f(s, V). Cut: Any partition (S, T) of V such that s ∈ S and t ∈ T

Take-home quiz No notes (except this one)

Problem: Maintain a dynamic collection of pairwise-disjoint sets= {S1, S2, .. S } Each set S; has one element distinguished as the representative element, rep[]

Shortest paths Single-source shortest paths Nonnegative edge weights

Algorithms Day 31 L18.2 Negative-weight cycles Recall: If a graph G = (V, E) contains a negative￾weight cycle, then some shortest paths may not exist. Example:

Consider a digraph G = (V, E) with edge-weight function w : E → R. The weight of path p = v1 → v2 → L → vk is defined to be

Definition. A directed graph (digraph) G = (V, E) is an ordered pair consisting of • a set V of vertices (singular: vertex)

Dynamic programming Design technique, like divide-and-conquer. Example: Longest Common Subsequence (LCS)

How large should a hash table be? Problem: What if we don’t know the proper size in advance? Goal: Make the table as small as possible, but large enough so that it won’t overflow (or otherwise become inefficient)