Answer:
See explaination
Explanation:
import java.util.Random;
public class Sample{
static class MinMax implements Runnable{
int []arr;
int start,end,min,max;
MinMax(int[]arr, int start,int end){
this.start=start;
this.end=end;
min=Integer.MAX_VALUE;
max=Integer.MIN_VALUE;
this.arr=arr;
}
atOverride
public void run() {
for(int i=start;i<=end;i++){ //search min and max form strant to end index
min=Math.min(min,arr[i]);
max=Math.max(max, arr[i]);
}
}
}
public static void main(String[] args) throws Exception{
long beginTime = System.nanoTime();
Random gen = new Random();
int n=100000000;
int[] data = new int[n]; //generate and fill random numbers
for(int i = 0; i < data.length; i++) {
data[i] = gen.nextInt()%1000000;
}
long endTime = System.nanoTime();
System.out.println("Done filling the array. That took " + (endTime - beginTime)/1000000000f + " seconds.");
//-----------------------------------------
System.out.println("Using 1 thread"); //1 thread
MinMax m1=new MinMax(data,0,n-1); //class object
Thread t1=new Thread(m1); //new thread
beginTime=System.nanoTime(); //start timer
t1.start(); //start thread
t1.join(0); //wait until thread finishes
endTime=System.nanoTime(); //end timer
System.out.println("Min,Max: "+m1.min+","+m1.max); //print minimum and maximum
System.out.println("Time using 1 thread " + (endTime - beginTime)/1000000000f + " seconds."); //print time taken
//-----------------------------------------
System.out.println("Using 2 thread");
m1=new MinMax(data,0,n/2);
MinMax m2=new MinMax(data,n/2+1,n-1);
t1=new Thread(m1);
Thread t2=new Thread(m2);
beginTime=System.nanoTime();
t1.start();
t2.start();
t1.join(0);
t2.join(0);
endTime=System.nanoTime();
System.out.println("Min,Max: "+ Math.min(m1.min,m2.min)+","+Math.max(m1.max,m2.max));
System.out.println("Time using 2 thread " + (endTime - beginTime)/1000000000f + " seconds.");
//-----------------------------------------
System.out.println("Using 3 thread");
m1=new MinMax(data,0,n/3);
m2=new MinMax(data,n/3+1,2*n/3);
MinMax m3=new MinMax(data,2*n/3+1,n-1);
t1=new Thread(m1);
t2=new Thread(m2);
Thread t3=new Thread(m3);
beginTime=System.nanoTime();
t1.start();
t2.start();
t3.start();
t1.join(0);
t2.join(0);
t3.join(0);
endTime=System.nanoTime();
System.out.println("Min,Max: "+ Math.min(Math.min(m1.min,m2.min),m3.min)+","+Math.max(Math.max(m1.max,m2.max),m3.max));
System.out.println("Time using 3 thread " + (endTime - beginTime)/1000000000f + " seconds.");
//-----------------------------------------
System.out.println("Using 4 thread");
m1=new MinMax(data,0,n/4);
m2=new MinMax(data,n/4+1,2*n/4);
m3=new MinMax(data,2*n/4+1,3*n/4);
MinMax m4=new MinMax(data,3*n/4+1,n-1);
t1=new Thread(m1);
t2=new Thread(m2);
t3=new Thread(m3);
Thread t4=new Thread(m4);
beginTime=System.nanoTime();
t1.start();
t2.start();
t3.start();
t4.start();
t1.join(0);
t2.join(0);
t3.join(0);
t4.join(0);
endTime=System.nanoTime();
System.out.println("Min,Max: "+ Math.min(Math.min(m1.min,m2.min),Math.min(m3.min,m4.min))+","+Math.max(Math.max(m1.max,m2.max),Math.max(m3.max,m4.max)));
System.out.println("Time using 4 thread " + (endTime - beginTime)/1000000000f + " seconds.");
}
}
