Decimal to Binary manipulations

For my first object oriented programming module, (it's been awhile since I did this in Comp Science, Memories!)

We were told to write an algorithm that would change a decimal number to binary numbers.

This was further extended to printing only the non trivial (sum of all bits not equal to one) and constant auto-correlating bits for number 0 to 2^14.

The code for decimal to bin

#include <string>

#include<fstream>

using namespace std;

//takes an int and returns the binary representation as a string

string decToBin(unsigned int intToConvert, unsigned int size){

register unsigned int tempInt = intToConvert;

string binRep="";

unsigned int i = 0;

do{

i++;

binRep = char((tempInt & 1u)+48u) + binRep;

tempInt >>= 1;

}while(i<size);

return binRep;

}

void assignment1Question1(){

const unsigned int size = 15u;

unsigned int maxBinarySize = 1<<size;

ofstream out("binary15.txt");

for (unsigned int i=0; i<maxBinarySize; i++){

out<<decToBin(i,size)<<endl;

}

}

int main(){

assignment1Question1();

return 0;

}

The code for const auto correlation and non trival

#include <string>

#include<fstream>

using namespace std;

//takes an int and returns the binary representation as a string

string decToBin(unsigned int intToConvert, unsigned int size){

register unsigned int tempInt = intToConvert;

string binRep="";

unsigned int i = 0;

do{

i++;

binRep = char((tempInt & 1u)+48u) + binRep;

tempInt >>= 1;

}while(i<size);

return binRep;

}

//MIT HAKMEM count

int sumOfBits(unsigned int test){

register unsigned int tmp;

tmp = test - ((test >> 1) & 033333333333)

- ((test >> 2) & 011111111111);

return ((tmp + (tmp >> 3)) & 030707070707) % 63;

}

//checks if an integer is of constant auto correlation

bool isConstAutoCor(unsigned int test, unsigned int size){

unsigned int shifted = test;

unsigned int autoCorNum = 0;

bool firstPass = 1;

//shift the bits, size-1 times to check for autocorrelation

for(unsigned int i=1; i < size; i++){

//shift the bits to the right

shifted = (shifted >> 1) | ( (1u & shifted) << (size-1));

//AND the shifted value with the test value to find the autoCorrelation number

unsigned int bitCount = sumOfBits(test & shifted);

//on first pass, set the autocorrelation number

if(firstPass==1){

firstPass=0;

autoCorNum = bitCount;

}

//on subsequent passes, check if the new autoCorrelation number is the same as the AC numbers found so far

else if(bitCount != autoCorNum){

return 0;

}

}

//only true if all autocorrelation numbers are equal

return 1;

}

//checks if an int is trivial

bool isTrivial(unsigned int test, unsigned int size){

unsigned int sum = sumOfBits(test);

if((sum <= 1) || (sum >= size-1)){

return 1;

}

return 0;

}

void assignment1Question2(){

const unsigned int size = 15u;

unsigned int maxBinarySize = 1<<size;

ofstream out("binary15a.txt");

for (unsigned int i=0; i<maxBinarySize; i++){

//we are looking for non trivial AND constant auto correlated binaries

if(!isTrivial(i, size)&&isConstAutoCor(i,size)){

out<<decToBin(i,size)<<endl;

}

}

}

int main(){

assignment1Question2();

}