What is output by the code below?
String[] ray;
ray = new String[4];
System.out.println( ray[0] );
What is output by the code below?
Integer[] ray;
ray = new Integer[4];
System.out.println( ray[3] );
What is output by the code below?
Integer[] ray;
ray = new Integer[4];
ray[1] = null;
ray[0] = new Integer(3);
ray[2] = new Integer(99);
System.out.println( ray[2] );
What is output by the code below?
Integer[] ray = {11,55,-4,909};
System.out.println( ray[3] );
What is output by the code below?
Double[] ray = {11.2,55.0,-4.5,909.0};
System.out.println( ray[1] );
What is output by the code below?
Double[] ray = {11.2,7.2,-4.5,909.0};
ray[1] = new Double(55.0);
System.out.println( ray[1] );
What is output by the code below?
Double[] ray = {3.2,5.7,6.3,1.9};
double x = 0;
for( double r : ray )
x += r;
System.out.println( x );
What is output by the code below?
Double[] ray = {3.1,5.2,6.3,1.4};
for( double r : ray )
r = 0;
System.out.println( ray[2] );
What is output by the code below?
String[] ray;
ray = new String[4];
ray[1] = "one";
System.out.println( ray[1] );
What is output by the code below?
String[] ray;
ray = new String[4];
ray[1] = "one";
ray[2] = "two";
ray[3] = "three";
System.out.println( ray[0] );
What do you call the condition that stops recursion?
What is returned the call fun(6) ?
public static int fun(int x)
{
if(x < 1)
return 1;
else
return x + fun(x - 1);
}
What is returned by the call fun(8) ?
public static int fun(int x)
{
if(x < 1)
return 1;
else
return x + fun(x - 1);
}
What is returned by the call fun(8) ?
public static int fun(int x){
if(x < 1)
return 1;
else
return x + fun(x - 2);
}
What is returned by the call fun(6) ?
public static int fun(int x){
if(x < 1)
return 1;
else
return x + fun(x - 2);
}
What is returned by the call wacky(4,6) ?
public static int wacky(int x, int y){
if(x <= 1)
return y;
else
return wacky(x - 1,y - 1) + y;
}
Which of the following sorts splits data into smaller lists, sorts the smaller lists, and then combines all of the sorted smaller lists back into one big list?
What is output by the code below?
ArrayList<Integer> r;
r = new ArrayList<Integer>();
r.add(1);
r.add(2);
r.add(3);
out.println( r.indexOf(100) );
What type of sort is funSort()?
public static void funSort( int[] ray )
{
for(int i=0; i< ray.length-1; i++)
{
int max = i;
for(int j = i+1; j<ray.length; j++)
{
if( ray[j] > ray[max] )
max = j;
}
if( max != i){
int temp = ray[max];
ray[max] = ray[i];
ray[i] = temp;
}
}
}
For the code at right to correctly implement a linear search, which of the following would correctly fill < blank 1 > ?
public static int find( ArrayList list, Object param )
{
for(int i=0; i < list.size(); i++)
{
if( list.get(i).equals(param) )
return i;
}
< blank 1 >
}
How many times would help() be called before list was sorted?
public void sort( int[] list, int front, int back)
{
int mid = (front+back)/2;
if( mid==front) return;
sort(list, front, mid);
sort(list, mid, back);
help(list, front, back);
}
private void help(int[] list, int front, int back)
{
int[] temp = new int[back-front];
int i = front, j = (front+back)/2, k =0;
int mid =j;
while( i<mid && j<back)
{
if(list[i]< list [j])
temp[k++]= list[i++];
else
temp[k++]= list[j++];
}
while(i<mid)
temp[k++]= list[i++];
while(j<back)
temp[k++]= list[j++];
for(i = 0; i<back-front; ++i)
list[front+i]=temp[i];
}
//code in the main
int[] list = {39,6,11,23,18,3,20,5,57};
sort(list, 0, list.length);
If ray is storing 10 elements, what is the maximum number of swaps funSort() could make in order to put the elements in order?
public static void funSort( int[] ray )
{
for(int i=0; i< ray.length-1; i++)
{
int max = i;
for(int j = i+1; j < ray.length; j++)
{
if( ray[j] > ray[max] )
max = j;
}
if( max != i){
int temp = ray[max];
ray[max] = ray[i];
ray[i] = temp;
}
}
}
If funSearch() will only work on sorted data, what type of sort is funSearch()?
public static int funSearch( int[] list, int val )
{
int len=list.length;
int bot=0, top=len-1;
int middle=0;
while( bot <= top )
{
middle=(bot+top)/2;
if (list[middle] == val)
return middle;
else
if(list[middle]>val)
top=middle-1;
else
bot=middle+1;
}
return -1;
}
funSort() will put the items in ray in what type of order?
public static void funSort( int[] ray )
{
for(int i=0; i< ray.length-1; i++)
{
int max = i;
for(int j = i+1; j < ray.length; j++)
{
if( ray[j] > ray[max] )
max = j;
}
if( max != i){
int temp = ray[max];
ray[max] = ray[i];
ray[i] = temp;
}
}
}
Which sort is shown below?
public void sort( int[] list, int front, int back)
{
int mid = (front+back)/2;
if( mid==front) return;
sort(list, front, mid);
sort(list, mid, back);
help(list, front, back);
}
private void help(int[] list, int front, int back)
{
int[] temp = new int[back-front];
int i = front, j = (front+back)/2, k =0;
int mid =j;
while( i<mid && j<back)
{
if(list[i]< list [j])
temp[k++]= list[i++];
else
temp[k++]= list[j++];
}
while(i<mid)
temp[k++]= list[i++];
while(j<back)
temp[k++]= list[j++];
for(i = 0; i<back-front; ++i)
list[front+i]=temp[i];
}
What would be the value of list after four passes of the help() method?
public void sort( int[] list, int front, int back)
{
int mid = (front+back)/2;
if( mid==front) return;
sort(list, front, mid);
sort(list, mid, back);
help(list, front, back);
}
private void help(int[] list, int front, int back)
{
int[] temp = new int[back-front];
int i = front, j = (front+back)/2, k =0;
int mid =j;
while( i<mid && j<back)
{
if(list[i]< list [j])
temp[k++]= list[i++];
else
temp[k++]= list[j++];
}
while(i<mid)
temp[k++]= list[i++];
while(j<back)
temp[k++]= list[j++];
for(i = 0; i<back-front; ++i)
list[front+i]=temp[i];
}
//code in the main
int[] list = {39,6,11,23,18,3,20,5,57};
sort(list, 0, list.length);
What is returned by the call wacky(2,6) ?
public static int wacky(int x, int y)
{
if(x <= 1)
return y;
else
return wacky(x - 1,y - 1) + y;
}
What is returned by the call fun(1) ?
public static int fun(int x)
{
if(x < 1)
return 1;
else
return x - fun(x - 3);
}
What is returned by the call wacky(5,5) ?
public static int wacky(int x, int y){
if(x <= 1)
return y;
else
return wacky(x - 1,y - 1) + y;
}
What is returned by the call fun(10) ?
public static int fun(int x)
{
if (x < 1)
return x;
else
return x + fun(x - 2);
}