Question

1. programmers often refer to a _____ search as a "divide and conquer" procedure

a. bubble

b. binary

c. division

d. split

2. you can add an item at any point in a _______ container and the array size expands automatically to accomodate the new item

a. arraylLst

b. Array

c. ResizableArray

d. array

3.int[][] myVals = {{2,4,6,8},{20,40,60,80};

Using the above two dimensional array, what is the value of myVals[1][2]?

a. 4

b.60

c. 6

d.40

Answer 1

1. Binary Search

This is because it works in following manner:

• works on sorted array and takes start of array as lower bound and length of array as upper bound
• while ( lower bound < upper bound )
• calculate middle index using ( mid=(start+end)/2 )
• if ( array[ mid ] == target ) return answer
• else if  ( array[ mid ] < target ) , makes recursive call with upper bound = mid
• else , makes recursive call with start = mid

this is why due to this branching in structure its said to be using divide and conquer approach

2 ArrayList in java is used as a resizable container or an dynamic array which expands on adding new element.

Note: an vector is used to do the same in C++, and list in python.

3. myVals[1][2] = 60 ,

because it refers to the second row and third column of the array.

Note: indexes always start from zero ( 0 ), so index 'i' is always 'i+1' physically. This is why i have written that it refers to second row ( by using [1] ) and third column ( by using [2] ).

Thank you.