Consider the following C functions in which size is the number of elements in the array E:

int MyX(int *E, unsigned int size){
 int Y = 0;
 int Z;
 int i,j,k;
 for(i = 0; i < size; i++)
       Y = Y + E[i];
 for(i = 0; i < size; i++)
   for(j = i; j < size; j++){
     Z = 0;
     for(k = i; k <= j; k++)
        Z = Z + E[k];
     if(Z > Y)
        Y = X;
   }
   return Y;
}

The value returned by the function MyX is the

Let G be a graph with n vertices and m edges. What is the tightest upper bound on the running time of Depth First Search on G, when G is represented as an adjacency matrix?

Consider a rooted n node binary tree represented using pointers. The best upper bound on the time required to determine the number of subtrees having exactly 4 nodes O(n^a Log^bn ). Then the value of a + 10b is _________

Given the following statements:

S1: A foreign key declaration can always be replaced by an equivalent check assertion in SQL.

S2: Given the table R(a,b,c) where a and b together form the primary key, the following is a valid table definition.

CREATE TABLE S (
 a INTEGER,
 d INTEGER,
 e INTEGER,
 PRIMARY KEY (d),
 FOREIGN KEY (a) references R)

Which one of the following statements is CORRECT?