Consider the depth-first-search of an undirected graph with 3 vertices P, Q, and R. Let discovery time d(u) represent the time instant when the vertex u is first visited, and finish time f(u) represent the time instant when the vertex u is last visited. Given that
d(P) = 5 units      f(P) = 12 units
d(Q) = 6 units      f(Q) = 10 units
d(R) = 14 unit      f(R) = 18 units
Which one of the following statements is TRUE about the graph

Let T be a depth-first search tree in an undirected graph G. Vertices u and v are leaves of this tree T. The degrees of both u and v in G are at least 2. Which one of the following statements is true?

Suppose that we have numbers between 1 and 100 in a binary search tree and want to search for the number 55. Which of the following sequences CANNOT be the sequence of nodes examined?

The following function computes the value of ^mC_n correctly for all legal values m and n (m≥1,n≥0 and m>n)

int func(int m, int n) 
{ 
     if (E) return 1; 
     else return(func(m -1, n) + func(m - 1, n - 1)); 
} 

In the above function, which of the following is the correct expression for E?