I want to echo out a total number per repeat - php

Question

I have created a small script which gives me random numbers. Now I want to create a list of this random number list with repeating numbers.
It should generate match numbers of this list of random numbers (A match number is a number which repeats)
For instance 4 – 6 – 9 – 32 – 34 – 31 – 5 – 32 (The match number here is 8 because after 8 numbers we have a repeater). I would like all the match numbers to be echo beside each other with a space in between.
Can someone help me?
I have tried creating an if statement but I can't get it working.
for ($rnd=1;$rnd<=50;$rnd++)
{
$random = mt_rand(0,100) . " ";
echo $random;
}

Answer 1

Explanation coming soon.
$numbers = array();
for($i = 1; $i <= 50; $i++) {
$number = mt_rand(0,100);
if(!isset($numbers[$number])) $numbers[$number] = array();
$numbers[$number][] = $i;
}
foreach($numbers as $key => $value) {
$start = '';
foreach($value as $k => $v) {
echo $start . $key . ' (Match Number: ' . $v . ')';
$start = ' - ';
}
echo '<br />';
}

Answer 2

If I don't misunderstood your question then this is what you want. Let's do this way-
<?php
$existing = [];
$repeat_numbers = [];
for ($rnd=1;$rnd<=50;$rnd++)
{
$random = mt_rand(0,100);
if(in_array($random,$existing)){
$repeat_numbers[] = $rnd; // pushing the repeating index
}
$existing[] = $random;
echo $random.PHP_EOL;
}
echo implode('-',$repeat_numbers);
?>
WORKING DEMO: https://3v4l.org/eEhB8
AS PER THE COMMENT
<?php
$existing = [];
$repeat_numbers = [];
for ($rnd=1;$rnd<=50;$rnd++)
{
$randoms[] = mt_rand(0,100);
}
echo implode('-',$randoms).PHP_EOL;
$i = 1;
foreach($randoms as $rnd){
if(in_array($rnd,$existing)){
$repeat_numbers[] = $i;
$i=1;
}
$existing[] = $rnd;
$i++;
}
echo implode('-',$repeat_numbers);
?>
WORKING DEMO https://3v4l.org/Xjc5X
AS PER THE LATEST COMMENT
<?php
$existing = [];
$repeat_numbers = [];
$randoms = explode('-','3-31-34-29-28-5-28-23-31-4-1-31-11-17-23-9-20-24-22-3-11-24-26-4-10');
$i = 1;
foreach($randoms as $rnd){
if(in_array($rnd,$existing)){
$repeat_numbers[] = $i;
$i=1;
$existing = []; // This like will do the magic for you
}
$existing[] = $rnd;
$i++;
}
echo implode('-',$repeat_numbers);
?>
WORKING DEMO: https://3v4l.org/hIT22
FINAL EDIT:
<?php
$existing = [];
$repeat_numbers = [];
$randoms = explode('-','4-9-13-18-19-34-23-9-9-13-44-5-13-13-88-26-29-27-34-67-65-83-26');
$i = 1;
foreach($randoms as $rnd){
if(in_array($rnd,$existing)){
$repeat_numbers[] = $i;
$i=1;
$existing = [];
}else{
$existing[] = $rnd;
$i++;
}
}
echo implode('-',$repeat_numbers);
?>
WORKING DEMO: https://3v4l.org/9j7iq
EDITED AGAIN:
<?php
$existing = [];
$repeat_numbers = [];
$randoms = explode('-','4-9-13-18-19-34-23-9-9-13-44-5-13-13-88-26-29-27-34-67-65-83-26');
//print_r($randoms);
$i = 0;
foreach($randoms as $rnd){
$i++;
if(in_array($rnd,$existing)){
$repeat_numbers[] = $i;
if(count($existing)==1){
$i=1;
}else{
$i=0;
}
$existing = [];
}
$existing[] = $rnd;
//print_r($existing);
}
echo implode('-',$repeat_numbers);
?>
WORKING DEMO: https://3v4l.org/VfIJY