Comp 182

Homework Assignments

Spring Semester 2015

HW #1 due: Tuesday 15 Sept 2015 @ the end of class

Putnam

Given the following method,

int fib( int n )

{

If (( n == 1) || ( n == 2)) return 1;

else return fib ( n – 1) + fib ( n – 2 )

}

Write the code and test it for n = 5, 7, 9 and

record the answers for each of the values.

a) Modify the code as shown below,

int fib( int n )

{

static boolean level = True;

static int k = 0;

if level == True

{ System.out.println ( “fib( “ + n + “) at level “ + k + ” ); “ );

// which should print “fib( 5 ) at level 0 “ for the first call.

level = False;

k++;

}

else if ( level == False )

{ System.out.print ( “fib( “ + n + “) at level “ + k + ” ); + “ );

Level = True;

}

)

If (( n == 1) || ( n == 2)) return 1;

else return fib ( n – 1) + fib ( n – 2 )

}

b) Implement the code and run it for n = 5, 7, 9, 10, 20, - 5 and

record the answers for each of the values.

c) Specify the preconditions and postconditions

for the fib method as defined above.

Use the level numbers and the printed statements

“fib( “ + n + “) at level “ + k + ” + “ “fib( “ + n + “) at level “ + k + ” ); “ ); i.e.,

“fib( 5 ) at level 0 “

“fib( 4) at level 1 + fib( 3 ) at level 1 “

to construct a tree which traces the entire Fibonacci computation.

SUBMIT

i. A printed copy of the code as specified in a above.

ii. A printed copy of the input values and their associated output values as documented in b above,.

iii. A precondition and postcondition report as specified in c above.

iv. A computer generated tree for n = 10

HW #2 due: Tuesday 15 Sept 2015 @ the end of class

Putnam

a) Read page 148 (A Recursive void Method: Writing a String Backward) to page159

b) Implement the code for writeBackwards2 and execute it for “Putnam”, “Bryncethin” and Your name.

c) Describe in detail what the writeBackwards2 code does for the submitted values.

d) Describe in meticulous detail how the writeBackwards2 code produces the given output.

SUBMIT

i. A printed copy of the code as specified in b above.

ii. A report based on c above.

iii. A very meticulous report that refers in detail to the code as specified in b above.

Archive Spring 2015

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