Question

Please finish this code and make it work. This is my homework and my professor wont allow me to change the code in main, it's a set of huge numbers need to sort by radixsort with bit operation.

#include <iostream>

using namespace std;

void radixLSD_help(int *items, int length, int bit)

{

  

// – Count number of items for each bucket.

  

// – Figure out where each bucket should be stored (positions

// of the first and last element of the bucket in the scratch

// array).

// – Copy each item to the corresponding bucket (in the scratch

// array).

// – Copy the scratch array back into items.

}

void radixLSD(int *items, int length)

{

int bit_per_item = sizeof(int) * 8;

  

int bit;

  

for (bit = 0; bit < bit_per_item; bit++)

{

radixLSD_help(items, length, bit);

cout << "Done with bit " << bit;

}

}

void sort(int *A,int n)

{

radixLSD(A, n);

}

void sort( int *A, int n);

int main()

{

int i, offset, j;

int B[10000000];

time_t t;

srand( (unsigned) time( &t ));

offset = rand()%10000000;

for( i = 0; i< 10000000; i++ )

{

B[i] = ((91*i)%10000000) + offset;

}

printf("Prepared array of 10 million integers; calling sort\n");

sort( B[], 10000000 );

printf("finished sort, now check result\n");

for( i=0, j=0; i < 10000000; i++ )

if( B[i] != i+ offset ) j++;

if( j == 0 )

printf("Passed Test\n");

else

printf("Failed Test. %d numbers wrong.\n", j );

}

Answer 1

Updated and working code:

#include <iostream>

using namespace std;

void radixLSD_help(int *items, int length, int bit)

{

  

// – Count number of items for each bucket.

  

// – Figure out where each bucket should be stored (positions

// of the first and last element of the bucket in the scratch

// array).

// – Copy each item to the corresponding bucket (in the scratch

// array).

// – Copy the scratch array back into items.

}

void radixLSD(int *items, int length)

{

int bit_per_item = sizeof(int) * 8;

  

int bit;

  

for (bit = 0; bit < bit_per_item; bit++)

{

radixLSD_help(items, length, bit);

cout << "Done with bit \n" << bit;

}

}

void sort(int *A,int n)

{

radixLSD(A, n);

}

void sort( int *A, int n);

int main()

{

int i, offset, j;

int B[10000000];

time_t t;

srand( (unsigned) time( &t ));

offset = rand()%10000000;

for( i = 0; i< 10000000; i++ )

{

B[i] = ((91*i)%10000000) + offset;

}

printf("Prepared array of 10 million integers; calling sort\n");

sort( B, 10000000 );

printf("finished sort, now check result\n");

for( i=0, j=0; i < 10000000; i++ )

if( B[i] != i+ offset ) j++;

if( j == 0 )

printf("Passed Test\n");

else

printf("Failed Test. %d numbers wrong.\n", j );

}