Math for coding interviews/Graph theory - dots and lines
Graph Theory Basics: Dots and Lines
A graph is just dots (called nodes or vertices) connected by lines (called edges). That is it. A social network is a graph: people are nodes, friendships are edges. A city map is a graph: intersections are nodes, roads are edges.
See it for yourself
Five circles on screen connected by lines between some pairs. Each circle is a node. Each line is an edge. If the lines have arrows, it is a directed graph (one-way streets). Without arrows it is undirected (two-way).
Graph theory - dots and lines
A graph is just dots (called nodes or vertices) connected by lines (called edges). That is it. A social network is a graph: people are nodes, friendships are edges. A city map is a graph: intersections are nodes, roads are edges.
Think of it this way: Any network you can think of: power grid, airline routes, the internet, your friend group. All graphs.
For algorithms: Graph algorithms (BFS, DFS) work on any of these structures. Understanding what a graph IS makes the traversal algorithms click immediately.
Real-world analogy
Any network you can think of: power grid, airline routes, the internet, your friend group. All graphs.
Why it matters in interviews
Graph algorithms (BFS, DFS) work on any of these structures. Understanding what a graph IS makes the traversal algorithms click immediately.