Consider a complete undirected graph with vertex set {0, 1, 2, 3, 4}. Entry W(ij) in the matrix W below is the weight of the edge {i, j}. $$$w = \left( {\matrix{ 0 & 1 & 8 & 1 & 4 \cr 1 & 0 & {12} & 4 & 9 \cr 8 & {12} & 0 & 7 & 3 \cr 1 & 4 & 7 & 0 & 2 \cr 4 & 9 & 3 & 2 & 0 \cr } } \right)$$$ What is the minimum possible weight of a path P from vertex 1 to vertex 2 in this graph such that P contains at most 3 edges?

The program below uses six temporary variables a, b, c, d, e, f.

a = 1 
b = 10 
c = 20 
d = a + b 
e = c + d 
f = c + e 
b = c + e 
e = b + f 
d = 5 + e 
return d + f

Assuming that all operations take their operands from registers, what is the minimum number of registers needed to execute this program without spilling?

Which data structure in a compiler is used for managing information about variables and their attributes?

The grammar $$S \to aSa\,|\,\,bS\,|\,\,c$$ is