Week 05 Laboratory Exercises

Download sixteen_in.c, or copy it to your CSE account using the following command:

cp -n /web/cs1521/23T3/activities/sixteen_in/files.cp/sixteen_in.c sixteen_in.c

Your task is to add code to this function in sixteen_in.c:

//
// given a string of binary digits ('1' and '0')
// return the corresponding signed 16 bit integer
//
int16_t sixteen_in(char *bits) {

    // PUT YOUR CODE HERE

    return 0;
}

Add code to the function sixteen_in so that, given a sixteen-character string containing an ASCII positional representation of a binary number, it returns the corresponding signed integer. For example:

./sixteen_in 0000000000000000
0
./sixteen_in 1111111111111111
-1
./sixteen_in 0011001100110011
13107
./sixteen_in 1111000011110000
-3856

When you think your program is working, you can use autotest to run some simple automated tests:

1521 autotest sixteen_in 

When you are finished working on this exercise, you must submit your work by running give:

give cs1521 lab05_sixteen_in sixteen_in.c

You must run give before Monday 23 October 12:00 (midday) (2023-10-23 12:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.

Download sixteen_out.c, or copy it to your CSE account using the following command:

cp -n /web/cs1521/23T3/activities/sixteen_out/files.cp/sixteen_out.c sixteen_out.c

Your task is to add code to this function in sixteen_out.c:

// given a signed 16 bit integer
// return a null-terminated string of 16 binary digits ('1' and '0')
// storage for string is allocated using malloc
char *sixteen_out(int16_t value) {

    // PUT YOUR CODE HERE

}

Add code to the function sixteen_out so that, given a 16-bit signed integer it returns a string containing sixteen binary digits ('0' or '1'). For example:

./sixteen_out 0
0000000000000000
./sixteen_out -1
1111111111111111
./sixteen_out 13107
0011001100110011
./sixteen_out -3856
1111000011110000

When you think your program is working, you can use autotest to run some simple automated tests:

1521 autotest sixteen_out 

When you are finished working on this exercise, you must submit your work by running give:

give cs1521 lab05_sixteen_out sixteen_out.c

You must run give before Monday 23 October 12:00 (midday) (2023-10-23 12:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.

Download bcd.c, or copy it to your CSE account using the following command:

cp -n /web/cs1521/23T3/activities/bcd/files.cp/bcd.c bcd.c

Your task is to add code to this function in bcd.c:

// given a  BCD encoded value between 0 .. 99
// return corresponding integer
int bcd(int bcd_value) {

    // PUT YOUR CODE HERE

    return 0;
}

Add code to the function bcd so that, given a 2 digit Binary-Coded Decimal (BCD) value, it returns the corresponding integer.

In binary-coded decimal format, each byte holds 1 decimal value (0 to 9), so each byte contains 1 decimal digit. For example:

./bcd 0x07
7
./bcd 0x0102             # note: 0x0102 == 258 decimal
12
./bcd 0x0402             # note: 0x0402 == 1026 decimal
42

When you think your program is working, you can use autotest to run some simple automated tests:

1521 autotest bcd 

When you are finished working on this exercise, you must submit your work by running give:

give cs1521 lab05_bcd bcd.c

You must run give before Monday 23 October 12:00 (midday) (2023-10-23 12:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.

Download packed_bcd.c, or copy it to your CSE account using the following command:

cp -n /web/cs1521/23T3/activities/packed_bcd/files.cp/packed_bcd.c packed_bcd.c

Your task is to add code to this function in packed_bcd.c:

// given a packed BCD encoded value between 0 .. 99999999
// return the corresponding integer
uint32_t packed_bcd(uint32_t packed_bcd_value) {

    // PUT YOUR CODE HERE

    return 0;
}

Add code to the function packed_bcd so that, given an eight-digit packed binary-coded decimal value, it returns the corresponding integer.

In packed binary-coded decimal format, each 4 bits holds 1 decimal value (0 to 9), so each byte contains 2 decimal digits. For example:

./packed_bcd 0x42         # note: 0x42 == 66 decimal
42
./packed_bcd 0x9999       # note: 0x9999 == 39321 decimal
9999
./packed_bcd 0x42424242   # note: 0x42424242 == 1111638594 decimal
42424242

When you think your program is working, you can use autotest to run some simple automated tests:

1521 autotest packed_bcd 

When you are finished working on this exercise, you must submit your work by running give:

give cs1521 lab05_packed_bcd packed_bcd.c

You must run give before Monday 23 October 12:00 (midday) (2023-10-23 12:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.