Shortest Path Problem

Finding the best route between two cities, given a complicated road network; or transmitting a message between two computers along a network of hundreds of computers, are all classified as the shortest path problem. ...

2018-12-18 · 5 min

The Assignment Problem

Given $n$ workers and $n$ jobs, and the cost $c_{ij}$ to train the $i$-th worker for the $j$-th job, find an assignment of one worker to each job which minimized the total training cost. ...

2018-12-16 · 5 min

Ramsey Numbers

Find the smallest integer $n$ that there must be either three mutual friends or three mutual strangers among $n$ people, suppose each pair of people are either friends or strangers? ...

2018-12-13 · 2 min

Catalan Numbers

In combinatorial mathematics, the Catalan numbers form a sequence of natural numbers that occur in various counting problems, often involving recursively-defined objects. ...

2018-12-05 · 6 min

Stirling Numbers

Various ways of distributing balls into cells. ...

2018-11-29 · 2 min

Hamming Code

It is extremely difficult, and often impossible, to prevent errors when data are stored, retrieved, operated on, or transmitted. ...

2018-11-19 · Updated: 2025-04-20 · 6 min

哥德尔不完备定理

Any mathematical system containing all the theorems of arithmetic is an incomplete system. ...

2018-11-05 · 4 min