sorting string with out using predefined java methods

[saikrishna cinux]

Hi, i am trying to sort some strings with out using predefined methods in java
but it is not working properly

can any one gind me the bugs in this program???

public class StringCmp{
public static void main(String args[])
{
String temp=new String("tree") ;
String str[]=new String[]{"zsai","krishna","az","laddu","c","a","zaaa","a"};
for(int i=0;i<str.length;i++)  //Outer loop -similar to bubble sort which takes O(N2) operations
{
for(int j=0;j<str.length;j++)  //inner loop
{
 

if(myStrCmp(str[i],str[j])>0) //using string comparision method
{
temp=str[i];
str[i]=str[j];
str[j]=temp;
    }
}
}
 
for(int i=0;i<str.length;i++)//display the sorted array
{
System.out.println(str[i]);
}
 
}
 
  public static int myStrCmp(String a,String b)//without using string comparision- Needed some corrections..
  {
int i=0;
int l=0;
int s=0;
int r=0;
if(a.length()>=b.length()) l=b.length();
else l=a.length();
 
for(i=0;i<l;i++)
{
if(a.charAt(i)>b.charAt(i)) //if this method is used then total operations or algorithm complexity is O(N3)
{
r=1;
break;
          }
 
}
            return r;
 
  }
 
/* public  static int myStrCmp(String a,String b)
 {
return (b.compareTo(a));
  }*/
 

}
 

:roll: :roll:

[Campbell Ritchie]

Your compare method is supposed to return a positive answer if a > b, zero if the two are the same, and a negative answer if a < b.
I can see no way to get a negative answer out of your compare method.

BTW. You will find it quicker to use arithmetic on the char values: you can calculate char1 - char2.

You are using l (don't use small L; it is too easy to confuse with the number 1) as the count of comparisons. But that will give a zero result if you compare the Strings "Camp" and "Campbell."

Initialise your loop counter in the for statement.
Initialise your temp value in the if block.

[Naseem Khan]

I tested your application and came to following conclusion....

if leftChar<rightChar then set r=-1;
if leftChar==rightChar then set r=0;
if leftChar>rightChar then set r=+1;

With these changes and slightly I changed inner for loop,

here is the code...

public class StringCmp{
public static void main(String args[]){
String temp=new String("tree") ;
String str[]=new String[]{"krishna", "zsai", "az", "laddu", "c", "a","zaaa","a", "java", "JSP"};
for(int i=0;i<str.length;i++){
for(int j=0;j<(str.length-1);j++)  { 
if(myStrCmp(str[j],str[j+1])==1) {
temp=str[j];
str[j]=str[j+1];
str[j+1]=temp;    
}
}
} 
for(int i=0;i<str.length;i++){
System.out.println(str[i]);
} 
}   
public static int myStrCmp(String a,String b){
int i=0;
int l=0;
int s=0;
int r=0;
if(b.length()<=a.length()) 
l=b.length();
else 
l=a.length(); 
for(i=0;i<l;i++){
if(a.charAt(i)>b.charAt(i)){
r=1;
break;         
}
if(a.charAt(i)<b.charAt(i)){
r=-1;
break;         
}
else {
continue;
}
}            
return r;   
}
}

Naseem

[Naseem Khan]

do one more thing, before passing it to myStrCmp(String a,String b), call trim() otherwise you will get wrong result.