Data Representation  Program Representation  
string int x[3] char x 0x9cd0f0ad 01101011 
Objects Arrays Primitive types Addresses bits 
Java code C++ code C code x86 code IBCM hexadecimal 
Highlevel language Lowlevel language Assembly language Machine code 
\( A[u][v] = \left\{ \begin{array}{l l} weight & \quad \text{if ($u$,$v$) $\in$ $E$}\\ 0 & \quad \text{if ($u$,$v$) $\notin$ $E$}\\ \end{array} \right. \)

One valid topological sort is: v1, v6, v8, v3, v2, v7, v4, v5
The weighted path length of \( v_1, v_2, \ldots , v_n \):
\( \sum_{i=1}^{n1}c_{i,i+1} \) where \( c_{i,i+1} \) is the cost of edge \( (v_i,v_{i+1}) \)


This is the same graph as in the Wikipedia article on Dijkstra's algorithm
From the ICPC MidAtlantic Regionals, 2009
And what constitutes a "highway"?
Original graph:
Possible spanning trees:
Edges: (v1,v2), (v1,v4), (v3,v4), (v4,v7), (v5,v7), (v6,v7)
Edges: (v1,v4), (v6,v7), (v1,v2), (v3,v4), (v4,v7), (v5,v7)