GOAL of algorithm

goal：—-communication

1. solve compucating problems
2. prove correctness
3. argue efficiency

Algorithms and computation

problems：

1. discrete mathematics 离散数学
   Inputs—-outputs
   …. ….

2. general problems arbitrary inputs

Exp: for birthday problems -maintain record
interview every student

procedure - algorithms

1. Correct:induction -归纳法 -就职 引起
   -base case 0 1… K=0
   assume

2. Effeciency -asymptotic analysis渐进分析
   O（）———- upper bound
   Omega（）——lower bounds
   Theta()——-both

Model of computation

Word - RAM :world - chunk- 64 bits
one read from mem
store that address in CPU
2-32 —-4 GB——Limitation
64 bits —-20 exabytes

学习顺序

Data structures and sorting—-> shortest paths, algorithms, and graphs——> dynamic programming