My current code generates 116 random numbers between the range of 34 and 76 and puts them into an array called $common.
for($i = 0; $i < 116; $i++){
$common[] = mt_rand(34, 76);
}
Is it possible to generate a random number from 2 groups of numbers? For instance, I want to have it pick 116 random numbers between 1-22 and 34-76.
1. Here's one way:
for($i = 0; $i < 116; $i++){
$common[] = array(mt_rand(1, 22), mt_rand(34, 76))[mt_rand(0, 1)];
}
Create an array of two random numbers, one from each range
Randomly pick array index 0 or 1
2. Well I'm bored, here's another:
$range = array_merge(range(1, 22), range(34, 76));
for($i = 0; $i < 116; $i++){
$common[] = $range[array_rand($range)];
}
Create an array of the numbers in the two ranges
Loop and randomly select from the range
In the second example you can also use:
$common[] = $range[mt_rand(0, count($range)-1)];
3. I'm waiting for lunch so here's another, similar to the first:
for($i = 0; $i < 116; $i++){
$common[] = mt_rand(0, 1) ? mt_rand(1, 22) : mt_rand(34, 76);
}
If random falsey 0 then generate from the first range
If random truthy 1 then generate from the second range
Related
I am trying to generate random values against '100' amount of value for 100 days. I am trying this way with for loop:
$total_days = 100;
$total_amount = 100;
$arr = array();
for($i = 0; $i < $total_days; ++$i)
{
$arr[] = rand(0.0, 1000.0);
}
$actual_sum = array_sum($arr);
for($i = 0; $i < $total_days; ++$i)
{
$arr[$i] *= $total_amount /$actual_sum;
//echo $arr[$i]."<BR><BR>";
$value = $arr[$i];
$genpackageroi = array(
'userid' => $userid,
'pkgid' => $pkgid,
'pkgcount' => $pkcount,
'amount' => $value,
'created_at' => $created_at,
'updated_at' => $updated_at,
);
DB::table('genpackageroi')->insert($genpackageroi);
}
The random generated value is like 0.1245444 OR 1.1245545, lots of numbers after decimal. While I just want this to be generated in float value like 1.21, 0.10, 2.25 like so. I it possible to do that?
But I want to generate the random numbers in round numbers. Because It
dose not matches the actual amount after generating all the random
numbers if we sum the generated random numbers. Like if I generates
the random numbers for amount of 100, then the sum of all generated
random numbers should 100. This is what actually I want.
What I gathered from your statement is that you want 100 floating numbers with 2 decimal places, and the sum of all these numbers should add up to 100.
This certainly is not the cleanest solution, but here goes:
$total_days = 100;
$total_amount = 100;
$arr = array();
for($i = 0; $i < $total_days; ++$i)
{
$arr[] = rand(0.0, 1000.0);
}
$actual_sum = array_sum($arr);
for($i = 0; $i < $total_days; ++$i)
{
$y = $arr[$i] * ($total_amount /$actual_sum);
$arr[$i] = round($y, 2); //round the numbers to 2 dp. Sum of all numbers could be greater than 100.
}
//hack, logic explained below
$maxElementKeys = array_keys($arr, max($arr)); //get max element's key
unset($arr[$maxElementKeys[0]]); //remove the max element from array, now the array contains 99 elements
$arr = array_values($arr); //rebase the keys
for($i = 0; $i < $total_days; ++$i)
{
if($i < ($total_days - 1) )
$value = $arr[$i];
else
$value = $total_amount - array_sum($arr); //to get the 100th number, subtract from 100 to ensure the total always adds up to 100
$genpackageroi = array(
'userid' => $userid,
'pkgid' => $pkgid,
'pkgcount' => $pkcount,
'amount' => $value,
'created_at' => $created_at,
'updated_at' => $updated_at,
);
DB::table('genpackageroi')->insert($genpackageroi);
}
The logic here is that round all numbers to 2dps. The total of which would in most cases exceed 100 by a few dps.
Next, get the max random number in the array and remove it from the array to make it an array containing 99 elements. The max number is removed to ensure that the sum of the new array stays below well clear of 100. So, to get the 100th element, get the sum of the new array and subtract that value from 100. Now, the total of all elements of the array and the 100th element that was just calculated should add up to exactly 100, with negligible chance for failure.
I have created a loop which returns a random number between two values. Cool.
But now I want the script to return the following value too: The number of unique numbers between two similar numbers.
Example:
4
5
8
22
45
3
85
44
4
55
15
23
As you see there is a double which is the four and there are 7 numbers inbetween. So I would like the script to echo these numbers two so in this case it should echo 7 but if there are more doubles in the list it should echo all the numbers between certain doubles.
This is what I have:
for ($x = 0; $x <= 100; $x++) {
$min=0;
$max=50;
echo rand($min,$max);
echo "<br>";
}
Can someone help me or guide me? I'm learning :)
Thanks!
So You need to seperate script for three parts:
getting randoms and save them to array (name it 'result'),
analyze them,
print (echo) results
Simply - instead of printing every step of loop, save them to array(), exit loop, analyze every item with other, example:
take i element of list
check is i+j element is the same
if is it the same - save j-i to second array() (name it 'ranges')
And after this, print two arrays (named by me as 'result' and 'ranges')
UPDATE:
Here's solution, hope You enjoy:
$result = array(); #variable is set as array object
$ranges = array(); #same
# 1st part - collecting random numbers
for ($x = 0; $x < 20; $x++)
{
$min=0;
$max=50;
$result[] = rand($min,$max); #here's putting random number to array
}
$result_size = count($result); #variable which is containg size of $result array
# 2nd part - getting ranges between values
for ($i = 0; $i < $result_size; $i++)
{
for ($j = 0; $j < $result_size; $j++)
{
if($i == $j) continue; # we don't want to compare numbers with itself,so miss it and continue
else if($result[$i] == $result[$j])
{
$range = $i - $j; # get range beetwen numbers
if($range > 0 ) # this is for miss double results like 14 and -14 for same comparing
{
$ranges[$result[$i]] = $range;
}
}
}
}
#3rd part - priting results
echo("RANDOM NUMBERS:<br>");
foreach($result as $number)
{
echo ("$number ");
}
echo("<br><br>RANGES BETWEEN SAME VALUES:<br>");
foreach($ranges as $number => $range)
{
echo ("For numbers: $number range is: $range<br>");
}
Here's sample of echo ($x is set as 20):
RANDOM NUMBERS:
6 40 6 29 43 32 17 44 48 21 40 2 33 47 42 3 22 26 39 46
RANGES BETWEEN SAME VALUES:
For numbers: 6 range is: 2
For numbers: 40 range is: 9
Here is your fish:
Put the rand into an array $list = array(); and $list[] = rand($min,$max); then process the array with two for loops.
$min=0;
$max=50;
$list = array();
for ($x = 0; $x <= 100; ++$x) {
$list[] = rand($min,$max);
}
print "<pre>";print_r($list);print "</pre>";
$ranges = array();
$count = count($list);
for ($i = 0; $i < $count; ++$i) {
$a = $list[$i];
for ($j = $i+1; $j < $count; ++$j) {
$b = $list[$j];
if($a == $b) {
$ranges[] = $j-$i;
}
}
}
print "<pre>";print_r($ranges);print "</pre>";
I have this math assignment that I should make into code.
I've tried all I thought of but I couldn't find a solution.
All this should be done without using php functions, only math operations.
You can use while, for, and such...
So I have number for example 9
Now I should create number of the length 9 which would be 999999999
If I had, for example, number 3, then the result should be 333.
Any ideas?
$gen = -1;
while($highest > 0) {
$gen = $highest + ($highest * 10);
$highest = $highest - 1;
}
echo $gen;
Here is a method that does not build a string; it uses pure math. (There will be many, many ways to do this task)
$x=9;
$result=0;
for($i=$x; $i; --$i){ // this looping expression can be structured however you wish potato-potatoe
$result+=$x*(10**($i-1)); // x times (10 to the power of (i-1))
}
echo $result;
// 999999999
*note: ** acts like pow() if you want to look it up.
Late edit: here is a clever, little loopless method (quietly proud). I am only calling range() and foreach() to demo; it is not an integral component of my method.
Demo: https://3v4l.org/GIjfG
foreach(range(0,9) as $n){
// echo "$n -> ",(integer)(1/9*$n*(10**$n)-($n/10)),"\n";
// echo "$n -> ",(1/9*$n*(10**$n)-(1/9*$n)),"\n";
// echo "$n -> ",(int)(1/9*10**$n)*$n,"\n";
// echo "$n -> ",(int)(10**$n/9)*$n,"\n";
echo "$n -> ",(10**$n-1)/9*$n,"\n";
}
Output:
0 -> 0
1 -> 1
2 -> 22
3 -> 333
4 -> 4444
5 -> 55555
6 -> 666666
7 -> 7777777
8 -> 88888888
9 -> 999999999
1/9 is the hero of this method because it generates .111111111(repeating). From this float number, I am using 10**$n to "shift" just enough 1s to the left side of the decimal point, then multiplying this float number by $n, then the float must be converted to an integer to complete.
Per #axiac's comment, the new hero is 10**$n-1 which generates a series of nines to the desired length (no float numbers). Next divide the nines by nine to generate a series of ones which becomes the perfect multiplier. Finally, multiply the series of ones and the input number to arrive at the desired output.
There are two operations you need to accomplish:
given a number $number, append the digit $n to it;
repeat operation #1 some number of times ($n times).
Operation #1 is easy:
$number = $number * 10 + $n;
Operation #2 is even easier:
for ($i = 0; $i < $n; $i ++)
What else do you need?
Initialization of the variable used to store the computed number:
$number = 0;
Put them in order and you get:
// The input digit
// It gives the length of the computed number
// and also its digits
$n = 8;
// The number we compute
$number = 0;
// Put the digit $n at the end of $number, $n times
for ($i = 0; $i < $n; $i ++) {
$number = $number * 10 + $n;
}
// That's all
If intval() is accepted:
$result = '';
$input = 9;
for($i=0; $i < $input; $i++){
$result .= $input;
}
$result = intval($result);
else:
$result = 0;
$input = 9;
for($i=0; $i < $input; $i++){
$factor = 1;
for($j = 0; $j < $i; $j++){
$factor *= 10;
}
$result += $input * $factor;
}
=>
9 + 90 + 900 + 9000 + 90000...
The problem statement is as following:
A particular kind of coding which we will refer to as "MysteryCode" is a binary system of encoding in which two successive values, differ at exactly one bit, i.e. the Hamming Distance between successive entities is 1. This kind of encoding is popularly used in Digital Communication systems for the purpose of error correction.
LetMysteryCodes(N)represent the MysteryCode list for N-bits.
MysteryCodes(1) = 0, 1 (list for 1-bitcodes,in this order)
MysteryCodes(2) = 00, 01, 11, 10 (list for 2-bitcodes,in this order)
MysteryCodes(3) =000, 001, 011, 010,110, 111, 101, 100 (list for 3-bitcodes,in this order)
There is a technique by which the list of (N+1) bitcodescan be generated from (N)-bitcodes.
Take the list of N bitcodesin the given order and call itList-N
Reverse the above list (List-N), and name the new reflected list: Reflected-List-N
Prefix each member of the original list (List-N) with 0 and call this new list 'A'
Prefix each member of the new list (Reflected-List-N) with 1 and call this new list 'B'
The list ofcodeswith N+1 bits is the concatenation of Lists A and B.
A Demonstration of the above steps: Generating the list of 3-bitMysteryCodesfrom 2-BitMysteryCodes
2-bit list ofcodes:00, 01, 11, 10
Reverse/Reflect the above list:10, 11, 01, 00
Prefix Old Entries with 0:000, 001, 011, 010
Prefix Reflected List with 1:110, 111, 101, 100
Concatenate the lists obtained in the last two steps:000, 001, 011, 010, 110, 111, 101, 100
Your Task
Your task is to display the last N "MysteryCodes" from the list of MysteryCodes for N-bits. If possible, try to identify a way in which this list can be generated in a more efficient way, than iterating through all the generation steps mentioned above.
More efficient or optimized solutions will receive higher credit.
Input Format
A single integer N.
Output Format
N lines, each of them with a binary number of N-bits. These are the last N elements in the list ofMysteryCodesfor N-bits.
Input Constraints 1 = N = 65
Sample Input 1
1
Sample Output 1
1
Explanation for Sample 1
Since N = 1, this is the (one) last element in the list ofMysteryCodesof 1-bit length.
Sample Input 2
2
Sample Output 2
11
10
Explanation for Sample 2 Since N = 2, these are the two last elements in the list ofMysteryCodesof 2-bit length.
Sample Input 3
3
Sample Output 3
111
101
100
$listN = 25;
$bits = array('0','1');
//check if input is valid or not
if(!is_int($listN))
{
echo "Input must be numeric!";
}
if($listN >= 1 && $listN <=65){
if($listN == 1){
echo '1'; exit;
}
ini_set('memory_limit', -1);
for($i=1; $i<=($listN - 1); $i++){
$reverseBits = array_reverse($bits);
$prefixBit = preg_filter('/^/', '0', $bits);
$prefixReverseBits = preg_filter('/^/', '1', $reverseBits);
$bits = array_merge($prefixBit, $prefixReverseBits);
unset($prefixBit, $prefixReverseBits, $reverseBits);
}
$finalBits = array_slice($bits, -$listN);
foreach($finalBits as $k=>$v){
echo $v."\n";
}
}
else{
echo "Invalid input!";
}
I have tried above solution, but didnt worked for input greater than 20.
for eg. If the input is 21, I got "Couldnt allocate memory" error.
It will be great if somebody figure out the optimized solutions...
The numbers follow a pattern which I transformed to below code.
Say given number is N
then create a N x N matrix and fill it's first column with 1's
and all other cells with 0's
Start from rightmost column uptil 2nd column.
For any column X start from bottom-most row and fill values like below:
Fill 2^(N - X + 1)/2 rows with 0's.
Fill 2^(N - X + 1) rows with 1's and then 0's alternatively.
Repeat step 2 till we reach topmost row.
Print the N x N matrix by joining the values in each row.
<?php
$listN = 3;
$output = [];
for ($i = 0; $i < $listN; $i++) {
$output[$i] = [];
for ($j = 0; $j < $listN; $j++) {
$output[$i][$j] = 0;
}
}
$output[$listN - 1][0] = 1;
for ($column = 1; $column < $listN; $column++) {
$zeroFlag = false;
for ($row = $listN - 1; $row >= 0;) {
$oneZero = 1;
if (!$zeroFlag) {
for ($k = 1; $k <= pow(2, $column) / 2 && $row >= 0; $k++) {
$output[$row][$listN - $column] = 0;
$row--;
$zeroFlag = true;
}
}
for ($k = 1; $k <= pow(2, $column) && $row >= 0; $k++) {
$output[$row][$listN - $column] = $oneZero;
$row--;
}
$oneZero = 0;
for ($k = 1; $k <= pow(2, $column) && $row >= 0; $k++) {
$output[$row][$listN - $column] = $oneZero;
$row--;
}
}
}
for ($i = 0; $i < $listN; $i++) {
$output[$i][0] = 1;
}
for ($i = 0; $i < $listN; $i++) {
print(join('', $output[$i]));
print("\n");
}
I would like to find out what is the most effective PHP script to evenly represent all numbers in a specific combinations subset.
Lottery problem example:
create 10 combinations each consisting of of 6 numbers
from set of number (1,2,3,4,5,6,7,8,9,10,11,12)
I know that from 12 numbers I can create 924 combinations each consisting of 6 numbers.
Since I can't afford to play 924 lines - I want to pick only 10 lines which represent evenly all my selected numbers.
So in this example it would be something like:
1-2-3-4-5-6
7-8-9-10-11-12
and 8 more lines
I'm trying to avoid combinations like:
1-2-3-4-5-6
1-2-3-4-5-7
1-2-3-4-5-8
... etc. which are almost the same; I want to evenly represent each number.
Hope that makes sense.
You can create a "pool" of the numbers you want to use, and randomly draw from that pool. For instance, if you want 10 combinations of 6 numbers each, that's a total of 60 numbers. But you want each of 1-12 represented evenly, so there will be 5 of each number. So start with an array containing 5 of each 1-12, and draw randomly from the array for each set of 6.
$pool = array();
for($i = 0; $i < 5; $i++)
for($x = 1; $x <= 12; $x++)
$pool[] = $x;
$result = array();
for($i = 0; $i < 10; $i++) {
$set = array();
for($x = 0; $x < 6; $x++) {
$key = array_rand($pool);
$set[] = $pool[$key];
unset($pool[$key]);
}
$result[] = $set;
}
// $result now contains 10 sets of 6 numbers each
Demo: http://ideone.com/NpO3h4
// how many numbers are in the set, starting from 1
$numbers = 12;
$set = array();
for ($i=1;$i>=$numbers;$i++)
{
array_push($set, $i);
}
// how many numbers in the subset
$count = 6;
$subSet = array();
while ($count > 0)
{
// get a random number from 1 to numbers in set
$rand=rand(0,$numbers-1);
array_push($subSet, $set[$rand]);
$count--;
}
// $subSet now contains a combination of 6 random numbers from 1 to 12
// keep refreshing
var_dump($subSet);
There you go, with explanations, is this what you wanted?
EDIT: I just noticed you said "the most effective way". This is not the most effective (in terms of memory used) way, but it's close.