comparing strings: how to do this??

choubix

hello all! 🙂

I am new here and I have a project that drives me crazy! (mostly because I have not coded for 2 years now...)

I am programming a simple lucky draw script where users have to select 4 numbers out of 16. I need to compare the selection made by the users to the winning numbers at the end of the competition.

for instance:
user 1: 01-03-11-14
user 2: 01-02-13-16
user 3: 02-14-08-16
user 4: 07-02-14-16

winning numbers: 07-16-14-02

so i need to record that:
user 1, 0 good number
user 2, 1 good number
user 3, 3 good numbers
user 4: all of them

order doesnt matter.

I have in the idea of exploding the array, storing each number as a different field and then checking each field for user 1, 2, 3 and 4 with the winning numbers.

the problem of such a thing is that it would take a longgggggggggggggg time to run given that apparently quite a lot of people are likely to play...

what would you suggest?
is there a script you know that compare such strings of characters and that I could use as a reference??

thanks!! 🙂
A.

halojoy

hi.
Where does such a row come from?
user 1: 01-03-11-14

Maybe there is a way to produce such a data record
in a format that is making checking winning numbers very easy in PHP.

Such is things you have to consider, when writing a application.
Use a data format that is fit to the functions.
Means doing some planning .....

choubix

hello halojoy,

thanks for taking the time to reply 🙂

I made a mistake that may have mislead you in my post: users make their selection on a grid. they have 16 choices: 01,02,03,04....,16

I get the user's selection through a form...
the order has no impact: a user selecting: 02, 14, 03, 11 wins if the winning numbers are 02, 03, 14, 11.

I would like to be able to plan a bit better but, as I said earlier: I am a bit rusty... (and programming is not my job even though I enjoyed it pretty much 😉 )

do you have a suggestion/strategy in mind so I can tackle this problem?

I'd like to get the script to run fast. all the ideas I have seem to be time consuming (not to program but to run)

thanks! 🙂

bradgrafelman

I would [man]explode() the winning numbers into an array on the '-' delimiter. Then, put all of the users in an array - ex. $user[1] = '01-03-11-14'. Loop through the users array, exploding each array item on the '-' just like you did for the winning numbers. Then, use a foreach() on the winning numbers array and use [man]array_search/man to see if each item in the winning numbers array exists in the current user's exploded array. You could have some sort of counter that you increment if a number is found (don't forget to reset this counter when moving on to the next user).

halojoy

if you already have your data
in a string / array of strings, like $user = '01-03-11-14'
then rest is not difficult.

bradgrafelman has already given you the functions that could be used
[man]explode[/man]
[man]foreach[/man]
[man]array_search[/man]
Adding a little mind work of your own, you can do this.
🙂

NogDog

If you put the values into an array, you can use array_diff():

<?php
$result = array(1, 3, 11, 14);
$correct = array(3, 14, 11, 1);
$wrong = array(14, 3, 1, 5);
// correct guess:
if(count(array_diff($result, $correct)) == 0)
{
   echo "Correct<br>\n";
}
else
{
   echo "Wrong<br>\n";
}
// wrong guess:
if(count(array_diff($result, $wrong)) == 0)
{
   echo "Correct<br>\n";
}
else
{
   echo "Wrong<br>\n";
}

bradgrafelman

D'oh! Didn't even think of using array_diff()! Good call.

NogDog

LOL - I've got good news and bad news about PHP. The good news: it has a lot of built-in functions to help you do a lot of different tasks. The bad news: I mean, it has a lot of built-in functions to help you do a lot of different tasks; more than I can ever hope to remember, I'm sure. 🙂

choubix

thanks guys for all these useful functions, that will clearly ease my job !

I'll start coding that right way (but may have to come back for some clarifications in case I am stuck somewhere)

really appreciate that you spent time on my question (and even provide me with chunks of code! 🙂 )