Let G = (V, E) be a directed graph, with source s ∈ V, sink t ∈
V, and nonnegative edge capacities {ce}. Give a polynomial-time
algorithm to decide whether G has a unique minimum s-t cut (i.e.,
an s-t of capacity strictly less than that of all other s-t
cuts).
Prove
1. Let f : A→ B and g : B → C . If g 。 f is one-to-one, then f
is one-to-one.
2. Equivalence of sets is an equivalence relation (you may use
other theorems without stating them for this one).
If G = (V, E) is a graph and x ∈ V , let G \ x be the graph
whose vertex set is V \ {x} and whose edges are those edges of G
that don’t contain x.
Show that every connected finite graph G = (V, E) with at least
two vertices has at least two vertices x1, x2 ∈ V such that G \ xi
is connected.
Consider the following grammar G:
E -> E + T | T
T -> T F | F
F -> F* | a | b
This grammar can be used to generate regular expressions over
the alphabet {a,b} with standard precedence rules.
Show your solution for each of the following 5 points:
1. Remove left recursion and write the
resulting grammar G1.
2. For the grammar G1, compute and write the
sets FIRST for every right hand side...
E ::= E + T | T
T ::= T * F | F
F ::= num | (E) Num ::= 0 | 1 | 2 | 3 | 4 | 5 | . . . . . .
.
Question: 1
a. Show the Left-most derivation for the expression: 5 * 7 + 6 * (1
+ 2).
b. Show the Right-most derivation for the expression: 5 * 7 + 6
* (1 + 2).
e) T F The larger the sample that is taken, the probability of
making a type 2 error increases.
f) T F We can never conclude that H0 is true based on taking a
random sample from from the population.
g) T F A stratified random sample is more preferred over a
simple random sample when the population can be divided into
homogeneous groups.
6. Let A = {1, 2, 3, 4} and B = {5, 6, 7}. Let f = {(1, 5),(2,
5),(3, 6),(x, y)} where x ∈ A and y ∈ B are to be determined by
you. (a) In how many ways can you pick x ∈ A and y ∈ B such that f
is not a function? (b) In how many ways can you pick x ∈ A and y ∈
B such that f : A → B...
1) a) Let k ≥ 2 and let G be a k-regular bipartite
graph. Prove that G has no cut-edge. (Hint: Use the bipartite
version of handshaking.)
b) Construct a simple, connected, nonbipartite 3-regular graph
with a cut-edge. (This shows that the condition “bipartite” really
is necessary in (a).)
2) Let F_n be a fan graph and Let a_n = τ(F_n) where τ(F_n) is
the number of spanning trees in F_n. Use deletion/contraction to
prove that a_n = 3a_n-1 - a_n-2...