Rewrite this code in Java please #include <iostream> #include <fstream> #include
ID: 3784003 • Letter: R
Question
Rewrite this code in Java please
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <ctime>
using namespace std;
long length = 1000;
const long max_length = 100000;
int list[max_length];
void read()
{
ifstream fin("random.dat", ios::binary);
for (long i = 0; i < length; i++)
{
fin.read((char*)&list[i], sizeof(int));
}
fin.close();
}
void bubbleSort()
{
int temp;
for(long i = 0; i < length; i++)
{
for(long j = 0; j< length-i-1; j++)
{
if (list[j] > list[j+1])
{
temp = list[j];
list[j] = list[j+1];
list[j+1] = temp;
}
}
}
}
void insertionSort()
{
int temp;
for(long i = 1; i < length; i++)
{
temp = list[i];
long j;
for(j = i-1; j >= 0 && list[j] > temp; j--)
{
list[j+1] = list[j];
}
list[j+1] = temp;
}
}
long partition(long left, long right)
{
int pivot_element = list[left];
int lb = left, ub = right;
int temp;
while (left < right)
{
while(list[left]< = pivot_element)
left++;
while(list[right]> pivot_element)
right--;
if (left < right)
{
temp = list[left];
list[left] = list[right];
list[right] = temp;
}
}
list[lb] = list[right];
list[right] = pivot_element;
return right;
}
void quickSort(long left, long right)
{
if (left < right)
{
long pivot = partition(left, right);
quickSort(left, pivot-1);
quickSort(pivot+1, right);
}
}
int main()
{
double t1, t2;
for (length = 1000; length <= max_length; )
{
cout << " Length : " << length << ' ';
read();
t1 = clock();
bubbleSort();
t2 = clock();
cout << "Bubble Sort : " << (t2 - t1)/CLK_TCK << " sec ";
read();
t1 = clock();
insertionSort();
t2 = clock();
cout << "Insertion Sort : " << (t2 - t1)/CLK_TCK << " sec ";
read();
t1 = clock();
quickSort(0, length - 1);
t2 = clock();
cout << "Quick Sort : " << (t2 - t1)/CLK_TCK << " sec ";
switch (length)
{
case 1000 :
length = 5000;
break;
case 5000 :
length = 10000;
break;
case 10000 :
length = 20000;
break;
case 20000 :
length = 50000;
break;
case 50000 :
length = 100000;
break;
case 100000 :
length = 100001;
break;
}
}
return 0;
}
Explanation / Answer
Here is the coverted Java version for you:
import java.util.*;
class SortingTime
{
static int length = 1000;
final static int max_length = 100000;
static int list[] = new int[max_length];
public static void read()
{
Scanner in = new Scanner(System.in);
in = new Scanner("random.dat");
for (int i = 0; i < length; i++)
{
list[i] = in.nextInt();
}
}
public static void bubbleSort()
{
int temp;
for(int i = 0; i < length; i++)
{
for(int j = 0; j< length-i-1; j++)
{
if (list[j] > list[j+1])
{
temp = list[j];
list[j] = list[j+1];
list[j+1] = temp;
}
}
}
}
public static void insertionSort()
{
int temp;
for(int i = 1; i < length; i++)
{
temp = list[i];
int j;
for(j = i-1; j >= 0 && list[j] > temp; j--)
{
list[j+1] = list[j];
}
list[j+1] = temp;
}
}
public static int partition(int left, int right)
{
int pivot_element = list[left];
int lb = left, ub = right;
int temp;
while (left < right)
{
while(list[left] <= pivot_element)
left++;
while(list[right]> pivot_element)
right--;
if (left < right)
{
temp = list[left];
list[left] = list[right];
list[right] = temp;
}
}
list[lb] = list[right];
list[right] = pivot_element;
return right;
}
public static void quickSort(int left, int right)
{
if (left < right)
{
int pivot = partition(left, right);
quickSort(left, pivot-1);
quickSort(pivot+1, right);
}
}
public static void main(String[] args)
{
double t1, t2;
for (length = 1000; length <= max_length; )
{
System.out.println(" Length : " + length);
read();
t1 = System.currentTimeMillis();;
bubbleSort();
t2 = System.currentTimeMillis();;
System.out.println("Bubble Sort : " + (t2 - t1) + " sec");
read();
t1 = System.currentTimeMillis();;
insertionSort();
t2 = System.currentTimeMillis();;
System.out.println( "Insertion Sort : " + (t2 - t1) + " sec");
read();
t1 = System.currentTimeMillis();
quickSort(0, length - 1);
t2 = System.currentTimeMillis();
System.out.println( "Quick Sort : " + (t2 - t1) + " sec");
switch (length)
{
case 1000 :
length = 5000;
break;
case 5000 :
length = 10000;
break;
case 10000 :
length = 20000;
break;
case 20000 :
length = 50000;
break;
case 50000 :
length = 100000;
break;
case 100000 :
length = 100001;
break;
}
}
}
}
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.