Java - searching all elements indexes in array equal to given number

Question

I have method searchSales() which is supposed to find all sales figures which are equal to the given sales figure.The application asks the user to enter the given sales figure using the keyboard and searches for it. If sales figure entered from the keyboard is found then the application displays sales figure/figures otherwise it displays an appropriate message. Well, i have a code which displays only first index of equal sales figure, for example: array has elements 1,2,3,3,4,5 and I want to find all indexes of [array] = 3. How can I do this?

public static void searchSales(int search[]){

        Scanner input = new Scanner(System.in);

        System.out.print("Enter sales figure you want to find: ");
        int target = input.nextInt();
        int index = -1;
        for (int i=0; i<search.length; i++){
            if (search[i] == target){
                index=i;
                break;
            }
        }
        if (index == -1){
            System.out.println("Sales figure not found");
        }
        else {
            System.out.printf("Sales figure found at branch %d",index+1);
        }
    }

Jack · Accepted Answer · 2012-09-11 02:26:12Z

1

 public static void searchSales(int search[]){

    Scanner input = new Scanner(System.in);
    System.out.print("Enter sales figure you want to find: ");
    int target = input.nextInt();
    int index = -1;
    for (int i=0; i<search.length; i++){
        if (search[i] == target){
            index=i;
            System.out.printf("Sales figure found at branch %d\n",index+1);

        }
    }
    if (index == -1){
        System.out.println("Sales figure not found");
    }

}

edited Sep 11, 2012 at 2:26

Jack

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answered Sep 11, 2012 at 1:51

rookiepupil

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1 Comment

aroth Over a year ago

The continue you have there is superfluous.

Vala · Accepted Answer · 2012-09-11 01:47:55Z

0

Remove the line that says break; (this line makes your code exit the loop), store each value in an array and print them out at the end, or print them out instead of storing them in the index variable.

answered Sep 11, 2012 at 1:47

Vala

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Comments

aroth · Accepted Answer · 2012-09-11 01:57:09Z

0

Use a List<Integer> to collect your matching indices. Something like:

    int target = input.nextInt();
    List<Integer> indices = new ArrayList<Integer>();
    for (int i=0; i<search.length; i++){
        if (search[i] == target){
            indices.add(i);
        }
    }
    if (indices.isEmpty()){
        System.out.println("Sales figure not found");
    }
    else {
        System.out.println("Sales figures found:  " + indices);
    }

edited Sep 11, 2012 at 1:57

answered Sep 11, 2012 at 1:47

aroth

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Comments

Sridhar · Accepted Answer · 2012-09-11 02:36:56Z

0

Use Arrays.asList and then use indexOf/lastIndexOf on the List. Something like:

ArrayList<Integer> sales = Arrays.asList(search)
int start = sales.indexOf(target);
int end = sales.lastIndexOf(target);
if(start==end){
    System.out.printf("Sales figure found at branch %d",start+1);
}
else{
    for(int i=start;i<=end-start;i++)
        if(sales.get(i)==target)
            System.out.printf("Sales figure found at branch %d",i+1);
}

edited Sep 11, 2012 at 2:36

answered Sep 11, 2012 at 2:20

Sridhar

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5 Comments

Sridhar Over a year ago

You're right. And sorting will destroy the index needed. Makes it a little messy. Updated.

obataku Over a year ago

No need to keep hitting sales.get(start), just compare against target :-) PS you can use listIterator(start)

Nataly Over a year ago

But how can I make it without using ArrayList<Integer>?

Sridhar Over a year ago

@Nataly - check the other answers if you don't want to use a collection.

Sridhar Over a year ago

@oldrinb - thanks for the suggestion - updated. Not sure listiterator(start) adds anything here because i'll have to iterate through the entire list rather than stop at end.

arshajii · Accepted Answer · 2012-09-11 03:00:15Z

0

In your case you don't really need to store anything anywhere, something like this should suffice:

public static void searchSales(int search[]){
    Scanner input = new Scanner(System.in);
    System.out.print("Enter sales figure you want to find: ");
    int target = input.nextInt();

    boolean found = false
    for (int i = 0 ; i < search.length ; i++)
        if (search[i] == target) {
            found = true;
            System.out.printf("Sales figure found at branch %d", i + 1);
        }
    if (! found)
        System.out.println("Sales figure not found");
}

highestSales is a different story. There, you do have to store stuff:

public static void highestSales(int[] nums) {
    List<Integer> list = new ArrayList<Integer>();
    list.add(0);
    for (int i = 1 ; i < nums.length ; i++) {
        if (nums[i] > nums[list.get(0)]) {
            list.clear();
            list.add(i);
        }
        else if (nums[i] == nums[list.get(0)])
            list.add(i);
    }
    System.out.println("Highest sales figure " + nums[list.get(0)] + " found at these branches");
    for (int i : list) System.out.println(i);
}

edited Sep 11, 2012 at 3:00

answered Sep 11, 2012 at 2:47

arshajii

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4 Comments

Nataly Over a year ago

Yes, this is better and works correctly!Thank you so much! But what do I need to do in case of highestSales() method?

arshajii Over a year ago

What do you mean by "what do I need to do in case of highestSales() method"? If you mean what you need to import: import java.util.ArrayList and import java.util.List.

Nataly Over a year ago

List<Integer> list = new ArrayList<Integer>();- it says that cannot find symbol and the second error in the last line - for (int i : list) System.out.println(i);- incompatible types. How can I fix it?Sorry, but I'm just a beginner in java))

Nataly Over a year ago

I fixed it.Thanks a lot))I'm trying to finish my application

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