java - Why bubble sort is taking more time then selection sort -

i trying various scenarios bubble sort , selection sort. know best case bubble sort o(n) if use break statement. lets if not using break statement, there not swaps (as have if condition it), , should take same or less time selection sort.

but strangely taking more time me.

note : have taken same data set(1 900000) sorted. , using sorted data set, none of algorithms have swappings.

please find program below :

 package sorting;  import java.util.arraylist; import java.util.calendar; import java.util.date; import java.util.list;  public class sorting<item extends comparable>//this item var/field can find while creatng object , hence non static {      list<item> list=new arraylist<item>();      public static void main(string args[])     {          sorting<integer> ss=new sorting<integer>();          system.out.println("adding item logic started : "+calendar.getinstance().gettime());         for(int i=0;i<90000;i++)         {             ss.list.add(i);          }         system.out.println("adding item logic ended : "+calendar.getinstance().gettime());         //selection sort started         calendar c1=calendar.getinstance();         system.out.println(c1.gettime());         ss.selectionsort(ss.list);          calendar c2=calendar.getinstance();         system.out.println(c2.gettime());         system.out.println("selection sort time taken in seconds : "+(c2.gettimeinmillis()-c1.gettimeinmillis())/1000);     //  system.out.println(ss.list);           //bubble sort started         ss.list=new arraylist<integer>();         for(int i=0;i<90000;i++)         {             ss.list.add(i);          }         calendar c3=calendar.getinstance();         system.out.println(c3.gettime());         ss.bubblesort(ss.list);          calendar c4=calendar.getinstance();         system.out.println(c4.gettime());         system.out.println("bubble sort time taken in seconds : "+(c4.gettimeinmillis()-c3.gettimeinmillis())/1000);     //  system.out.println(ss.list);     }      void selectionsort(list<integer> list)     {         for(int i=0;i<list.size();i++)         {             int target=(integer)list.get(i);             int pos=0;              for(int j=i+1;j<list.size();j++)             {//system.out.println(i+"  "+j);                 if(target>(integer)list.get(j))                 {                     pos=j;                     target=(integer)list.get(j);                 }             }             if(pos!=0)             {                 integer temp=(integer)list.get(i);                 list.set(i, (integer)list.get(pos));                 list.set(pos, temp);               }            }     }      void bubblesort(list<integer> list)     {          for(int i=list.size()-1;i>0;i--)         {             int status=0;             for(int j=0;j<=i-1;j++)             {                 //system.out.println(i+"  "+j);                 if((integer)list.get(j)>(integer)list.get(j+1))                 {                     int temp=(integer)list.get(j+1);                     list.set(j+1, (integer)list.get(j));                     list.set(j, temp);                     status++;                 }             }             //if(status==0)break;         }     } } 

this program 85 percent giving more time bubble sort , double of insertion sort taking.

adding item logic started : fri jun 26 02:47:13 pdt 2015 adding item logic ended : fri jun 26 02:47:13 pdt 2015 fri jun 26 02:47:13 pdt 2015 fri jun 26 02:47:58 pdt 2015 selection sort time taken in seconds : 44 fri jun 26 02:47:58 pdt 2015 fri jun 26 02:48:46 pdt 2015 bubble sort time taken in seconds : 56 

well, see in code, number of iterations in both algorithms same

for(int i=0;i<list.size();i++)     for(int j=i+1;j<list.size();j++) 

would same as

for(int i=list.size()-1;i>0;i--)     for(int j=0;j<=i-1;j++) 

so difference should rely on what's happening inside each iteration (i taking inner part of loop, other omit).

in bubble sort:

if((integer)list.get(j)>(integer)list.get(j+1)) {     int temp=(integer)list.get(j+1);     list.set(j+1, (integer)list.get(j));     list.set(j, temp);     status++; } 

as list sorted, won't inside if, have 2 list.get(something).

in selection sort:

if(target>(integer)list.get(j)) {     pos=j;     target=(integer)list.get(j); } 

but won't inside if, 1 list.get(something).

in short, selection sort doing less operations in each iteration, may makes program run faster.