how to compare the elements of the two arraylists al1,al2

[raj reddy]

hi Sanjeev


The code is exactly working fine.

BUT I NEED TO GET THE PRIZE LEVELS DEPENDING UPON THE NUMBER OF COUNTS;


I HAVE GIVEN THE count++ in the for loop.


but am not getting the updated count value ;



can u please check and resubmit the code whether the count++ i have given in the loop is at correct location or not.





import java.util.ArrayList;
public class CompareList
{

public static void main(String[] args){
ArrayList list1 = new ArrayList();
list1.add(10);
list1.add(20);
list1.add(30);
list1.add(40);
ArrayList list2 = new ArrayList();
list2.add(11);
list2.add(12);
list2.add(13);
list2.add(14);
list2.add(15);
list2.add(16);
list2.add(17);
list2.add(18);
list2.add(19);
list2.add(20);

int s = 1;

int count=1;

for (int i=0;i<list2.size();i++) {
if(s <= 4){
System.out.println("here..:"+list2.get(i));
for (int j=0;j<list1.size(); j++) {
if(list2.get(i).equals(list1.get(j)))

count++;

System.out.println("equals..:"+list1.get(j));
}
s++;
}else{
System.out.println("Checked Four elements, Now checking next Four");
s = 1;
i--;
}
}


if(count==al2.size()-4) {
System.out.println("The level of the prize is FOUR "+count);
}else if(count==al2.size()-3) {
System.out.println("The level of the prize is THREE"+count);
} else if(count==al2.size()-2) {
System.out.println("The level of the prize is TWO "+count);
} else if(count==al2.size()-1) {
System.out.println("The level of the prize is ONE "+count);
} else if(count==al2.size()-0) {
System.out.println("The level of the prize is ZERO "+count);
}
else System.out.println("There is no prize level ");

}
}

[sanjeevtarar]

I did not understand your count logic.
You will get count value : Number of matches (start count with 0).
count is giving correct value

check this code

import java.util.ArrayList;
public class CompareList
{

public static void main(String[] args){
	ArrayList list1 = new ArrayList();
	list1.add(10);
	list1.add(20);
	list1.add(30);
	list1.add(40);
	ArrayList list2 = new ArrayList();
	list2.add(11);
	list2.add(12);
	list2.add(13);
	list2.add(14);
	list2.add(15);
	list2.add(16);
	list2.add(17);
	list2.add(18);
	list2.add(19);
	list2.add(20);

	int s = 1;

	int count=0;

		for (int i=0;i<list2.size();i++) {
			if(s <= 4){
				System.out.println("Values..:"+list2.get(i));
				for (int j=0;j<list1.size(); j++) {
						if(list2.get(i).equals(list1.get(j))){
							count++;
							System.out.println("equals..:"+list1.get(j));
						}
				}
				s++;
			}else{
				System.out.println("Checked Four elements, Now checking next Four");
				s = 1;
				i--;
			}
		}

		System.out.println(count);
		if(count==list2.size()-4) {
		System.out.println("The level of the prize is FOUR "+count);
		}else if(count==list2.size()-3) {
		System.out.println("The level of the prize is THREE"+count);
		} else if(count==list2.size()-2) {
		System.out.println("The level of the prize is TWO "+count);
		} else if(count==list2.size()-1) {
		System.out.println("The level of the prize is ONE "+count);
		} else if(count==list2.size()-0) {
		System.out.println("The level of the prize is ZERO "+count);
		}
		else System.out.println("There is no prize level ");

	}
}

What exactly mean...of .... if(count==list2.size()-4)

[raj reddy]

if(count==list2.size()-3) means






the count value will be added if one value or more values are matchable for every loop



this count should be added by using count++



ie for every 4 values (which exist in list1) and for every 4 values (which exist in list2)



suppose 2 values were there means count will be 2 for that loop




if(count==list2.size()-3) means




in the above one list2.size()-3 is





the actual value of list2.size() is 4


if we subtract 1 value from that one is 3



so


if 3(this is count value)=3 (this is list2.size()-3) value

{

System.out.println("The level of the prize is THREE"+count);
}



SO IN THE ABOVE CODE IN WHICH FOR LOOP I HAVE TO PLACE THE count++

[raj reddy]

Hi sanjeev








Requirement : count variable should increment upto the last comparison of the arrays.

ie count=1,2,3,4,5....upto last comparison of the arrays like that


and also count variable should be increased if and only if the two arrays values are equal

everything is fine but only the count variable is not incrementing for the last comparison of the arrays

Let us think that there are two arrays al1 and al2;




MY CODE:

al1={1,2,3}


al2=(1,2,3,4,5,6,7,8,9}



int count=0;


for (int i=0;i<al1.size();i++) {
{

for (int j=0;j<al2.size(); j++) {



if(al1.get(i).equals(al2.get(j)))

count++;


}


Actually the count variable should increment for every comparison of the al1 and al2.


MY PROBLEM IS : THe variable is incrementing fine for every comparison , but for the last comparison of the arrays the count variable is not incrementing.


can u validate the count variable such a way that i have to get the last comparison value of the two arrays.

PLS SEND ME THE UPDATED CODE

[Eranga]

What you mean that last comparison not increment the counter. It should be 3, and seems to me your code give the correct value.

[raj reddy]

hi eranga

when the two arrays were comparing


ie if(al1.get(i).equals(al2.get(j)))


the count variable should be incremented


but for the last comparison of the values in the arrays

the count variable is not incrementing

if u have any queries reply me

[raj reddy]

hi Eranga


the count variable should be incremented for every element comparison of the arrays

for eg

int count=0;

al1.(2)=al2.(2)
count++;

the above arrays were equal, so the count variable will be incremented to 1;

then go for next comparison

al1.(3)=al2.(3)
count++;

the count variable will be incremented to 2;


like that the count variable will be go on incrementing if the number of equal comparisons were there


what my problem is :


the count variable is not incrementing for the last comparison of the arrays


can u check in the code i have sent above

[Eranga]

Your code give the correct value.

May be you refer the count variable in wrong place. According to your array lists the count variable hold the 3 as final result. It can't be 2 as you said.

[sreeg]

I just found this thread. I case any one is interested:

import java.util.ArrayList;
public class CompareList
{

@SuppressWarnings("unchecked")
public static void main(String[] args){
ArrayList list1 = new ArrayList();
list1.add(10);
list1.add(20);
list1.add(30);
list1.add(40);
ArrayList list2 = new ArrayList();
list2.add(11);
list2.add(12);
list2.add(13);
list2.add(14);
list2.add(15);
list2.add(16);
list2.add(17);
list2.add(18);
list2.add(19);
list2.add(20);
ArrayList list3 = new ArrayList();
Object sree = null;

for (int i=0;i<list2.size();i++) {
for (int j=0;j<list1.size(); j++) {
if(list2.get(i).equals(list1.get(j)))
{
System.out.println("equals..:"+list1.get(j));
sree = list1.get(j);
}
if(list2.get(i).equals(list1.get(j)))
{
list3.add(sree);
}
}


}
System.out.println("Final list3:" + list3);
}
}

[Eranga]

Not a bad approach. Thanks for sharing.

[shalini_priya]

How to find out the starting position of the second array from the first array without using the API methods?


Let's say we have the following two lists:
int [] a1=[2, 7, 8, 4, 6, 0, 3, 9, 1, 5]
int [] a2=[6, 0, 3]

Note: The 1st array is an unsorted array. It should not be sorted.

Please help me out asap.

[Eranga]

How to find out the starting position of the second array from the first array without using the API methods?


Let's say we have the following two lists:
int [] a1=[2, 7, 8, 4, 6, 0, 3, 9, 1, 5]
int [] a2=[6, 0, 3]

Note: The 1st array is an unsorted array. It should not be sorted.

Please help me out asap.

Then you've to define your own logic/algorithm for that. Just as a hint, search through the two arrays and keep tack on the same order in both arrays. Once the same element found in both arrays keep track on the next element, either same or not.

[shalini_priya]

Thanks. I have managed to do the code with your help

[Eranga]

You are welcome. If you like just post your code to see others. Anyone can useful your code.