Assignment: Bit Operations with Python Bit operations play a crucial role in designing efficient algorithms and we will be dealing with such operations throughout the course multiple times. I'm assuming that bit operations are review for you, but I'm also assuming that you've had very little practice programming with them. This selfstudy project is to show you a little programming with bit operations, and to give you a program (bit.cpp) that can help you practice bit operations and hexadecimal. Learning Objectives: Here you are to re-implement bit.cpp in Python as bit.py.

/* bit.cpp -- a program to help you understand binary arithmetic.

*/

#include #include #include #include #include using namespace std;

/* This is how we're holding a number. It facilitates printing out the number. */

class Number { public: unsigned long long d; /* The number. */ string hex; /* Its representation in hex (16 hex digits with a 0x in front). */ string binary; /* Its representation in binary */ string To_String(); /* This creates a bigger string, which is kind of formatted. */ };

/* This returns a "formatted" string for a number. */

string Number::To_String() { char buf[200]; string s;

sprintf(buf, "%21llu %s %s", d, hex.c_str(), binary.c_str()); s = buf; return s; }

Number *number_from_ull(unsigned long long v) { Number *n; int i; char buf[200]; /* Create the Number class instance, and set the strings. */

n = new Number; n->d = v;

/* Set the hexadecimal using sprintf. */

sprintf(buf, "0x%016llx", v); n->hex = buf;

/* For the binary, examine each bit by doing AND with one left-shifted the proper number of bits. "1ULL" forces the compiler to treat one as an unsigned long long. Otherwise, if you shift it more than 31 bits, it will treat one as an integer, and turn it into zero. */

n->binary.resize(64, '0'); for (i = 0; i < 64; i++) if (v & (1ULL << i)) n->binary[64-i-1] = '1';

return n; }

/* This creates a number from a string, which is either decimal, hexadecimal (starting with 0x), or binary (starting with B). It creates all of the string representations. */

Number *number_from_string(string &s) { unsigned long long v; unsigned long long i; int b; Number *n; char buf[100];

v = 0;

if (s.size() == 0) return NULL;

/* Convert from binary if the string begins with 'B' */

if (s[0] == 'B') { if (s.size() == 1) return NULL; if (s.size() > 65) return NULL; for (i = 0; i < s.size()-1; i++) { b = s[s.size()-i-1]; if (b != '0' && b != '1') return NULL; if (b == '1') v |= (1ULL << i); }

/* Convert from hex if the string begins with "0x" */

} else if (s.substr(0, 2) == "0x") { if (s.size() == 2 || s.size() > 18) return NULL; if (sscanf(s.c_str(), "0x%llx", &v) != 1) return NULL;

/* Attept to convert from decimal. */

} else { if (sscanf(s.c_str(), "%llu", &v) != 1) return NULL; }

return number_from_ull(v); }

/* Number_from_ull just converts the number to a string and then calls "number_from_string." */

int main() { Number *A, *B, *C; string sa, sb, sop; int error;

printf("When entering numbers, you can enter: "); printf(" A normal decimal number as big as 2^{64}-1. "); printf(" A number in hex up to 16 digits, starting with 0x. "); printf(" A number in binary up to 64 digits, starting with B. ");

while (1) { error = 0; C = NULL;

/* Grab A, B and the operator. */

printf("Enter a problem: number AND|OR|XOR|LS|RS|ANDNOT number: "); fflush(stdout);

if (! (cin >> sa >> sop >> sb)) exit(1);

/* Convert A and B to instances of the Number class, and error check. */

A = number_from_string(sa); B = number_from_string(sb); if (A == NULL) { printf("Bad format for the first number. "); error = 1; } if (B == NULL) { printf("Bad format for the second number. "); error = 1; } /* Do the operation if we haven't had an error so far. */

if (error == 0) { if (sop == "AND") { C = number_from_ull(A->d & B->d); } else if (sop == "OR") { C = number_from_ull(A->d | B->d); } else if (sop == "XOR") { C = number_from_ull(A->d ^ B->d); } else if (sop == "LS") { C = number_from_ull(A->d << B->d); } else if (sop == "RS") { C = number_from_ull(A->d >> B->d); } else if (sop == "ANDNOT") { C = number_from_ull(A->d & (~B->d)); } else { printf("Bad operator. "); error = 1; } } /* If everything was successful, print the results. */

if (error == 0) { printf(" "); printf("Operator: %s ", sop.c_str()); printf("A: %s ", A->To_String().c_str()); printf("B: %s ", B->To_String().c_str()); printf("C: %s ", C->To_String().c_str()); printf(" "); }

/* Free up memory: Call delete on anything that you created with new. */

if (A != NULL) delete A; if (B != NULL) delete B; if (C != NULL) delete C; }

exit(0); }

----------------------------

class Number: def __init__(self, v): "CODE HERE to intialize the object" def toString(self): "CODE HERE to print the number in mulitple formats: decimal, hex, binary"

""" Dont change this part, it's used for grading.

inputStr would be the input sentence like: 5 AND 9

"""

while True: print("When entering numbers, you can enter:") print(" A normal decimal integer number as big as 2^{64}-1.") print(" An integer number in hex up to 16 digits, starting with 0x.") print(" An integer number in binary up to 64 digits, starting with 0b.") print("Enter a problem: number AND|OR|XOR|LS|RS|ANDNOT number:")

try: inputStr = input() except (EOFError): exit()

""" CODE HERE to interpret inputs/operators, and perform operations.

"""

""" Outputs, dont change the following because we're grading based on this. We're going to grade by testing it with a .txt file with some sample inputs, and we expect to see results like:

Operation: AND A: 5 0x5 0b101 B: 9 0x9 0b1001 C: 1 0x1 0b1

(this example takes input: 5 AND 9 )

Make sure your code reads the input correctly """ # output print(" Compute Result:") print(" Operation: ", operation) print(" A: ", numberA.toString()) print(" B: ", numberB.toString()) print(" C: ", numberC.toString())