CS1020 Lab 0 Discussion Given 2 bits, determine the result of the given binary operation - PowerPoint Presentation

Slide1

CS1020

Lab 0 Discussion

Given 2 bits, determine the result of the given binary operation (AND or OR).

Reading inputs:Reading from standard input:

Probrem 1: HelloWorld

Scanner sc = new Scanner(System.in);

Type 1: read N operations

N = sc.nextInt();for (int i = 0; i < N; i++) { operator = sc.next(); firstBit = sc.nextInt(); secondBit = sc.nextInt(); // process the result accordingly}

2

Problem 1:

HelloWorld

Type 2: read until special character ‘0’

while (true) {

operator =

sc.next();

if (operator.equals(specialCharacter)) break;

bit1 = sc.nextInt(); bit2 = sc.nextInt(); // process the result accordingly}Type 3: read until end of filewhile (sc.hasNext()) { operator = sc.next(); bit1 = sc.nextInt(); bit2 = sc.nextInt

(); // process the result accordingly

}

3

Problem 1:

HelloWorld

A string S[0…n-1] is palindrome

iffS[0] = S[n-1], S[1] = S[n-2], S[2] = S[n-3], …i.e. S[i]=S[n-1-i] for every i.Problem 2: Palindrome

for (

int i = 0; i < len; i++) { if (s.charAt(i) != t.charAt(

len - i - 1)) { palindrome = false; break;

}}

Alternatively, just reverse the second string and use the equals() method

Use

compareTo( ) method (can be used for objects in Java).

When comparing two strings, a and b:int

comparisonResult = a.compareTo(b);

The method returns:0 if they are lexicographically same >= 1 if a is lexicographically ‘larger’ than b <= -1 if a is lexicographically ‘smaller’ than b

Problem 3: Compare

ADDITIONAL SLIDES

Comparing Outputs

8

Suppose your java

classname is Test, the input filename is “test.in” and the correct output filename is “

test.out”Run your program and store your program’s output in “test.tmp

”java Test < test.in > test.tmpCompare test.out and test.tmp. diff test.tmp test.outIf diff doesn’t produce any output, then “test.tmp

” and “

test.out

”

are

exactly the same (your program

produces the

correct output)

Comparing Outputs (8 times)

9

java Test < test1.

in > test1.tmpdiff test1.tmp test1.out

java Test < test2.in > test2.tmp

diff test2.tmp test2.outjava Test < test3.in > test3.tmpdiff test3.tmp test3.outjava Test < test4.in > test4.tmpdiff test4.tmp test4.out... ... ...

...

..

.

...

Comparing Outputs (8 times)

Faster way using a loop10

for

i in {1 .. 8}do

java Test < test$i.in > test$i.tmp

diff test$i.tmp test$i.outdone//YEAY

END OF FILE