PHP Challenge

[mshort1985]

Hi folks, I have started searching the net for programming challenges just to test my self on what i’ve been learning, this is the first one I attempted. It seems simple but I was wondering if some more experienced Programmers might look over my solution and tell me if there would have been a more effient way to complete it. Thanks :)

the problem is as follows:
Your program should be able to open a text file and read its contents. The file will consist only of LOWERCASE letters and numbers 0-9. The file will be formatted such that there is only one alphanumeric character per line. Example file:

5

a

n

7

4

n

6

1

0

y

w

a

Your program must read each line and store the data in a data structure of your choice. Parse through your structure and print out the following information:

1. The sum of all the individual digits.
2. How many times each character appeared in the file.

Example output for the example above would be:

Sum = 23

a = 2

n = 2

w = 1

y = 1

Your program should work with any size file.

and here is my solution:

//read the file

$myFile = "numbers.txt";

$haystack = file_get_contents($myFile);



//Form an array from the data gathered from the file

$theData = str_split($haystack);



//Add up the values and echo out the sum.

echo "Sum: " . array_sum($theData) . "
";

//Strip out any duplicate values from the array and then sort the array

$theData = array_unique($theData);

sort($theData);



//remove the first value of the array to get rid of any Null values.

array_shift($theData);



//loop through the array counting how many times each value appears in the haystack string and then echoing them out.

foreach($theData as $needle) {

echo "$needle: " . substr_count($haystack, $needle) . "
";

}



?>

Thanks in advance :)

[djpic]

Looks very simple. Personally, I would have looped through each line of the text file, check each line if it is a integer or character. If it is was an integer, add it to a $sum variable. If it was a character, then place that in an array like this:

$char[$currentLineValue] = $currentLineValue;

$char[$currentLineValue]++;

Then to display the results, echoed out the $sum and then:

foreach($char as $character) {

// echo out variables here

}

[ddliu]

Here is my solution:

$file='numbers.txt';

$fp=fopen($file,'r');



$sum=0;

$chars=array();



//parse line by line to save memory

while(false!==$line=fgets($fp)){

$line=trim($line);

if(is_numeric($line)){

$sum+=$line;

}

else{

if(!isset($chars[$line])){

$chars[$line]=1;

}

else{

$chars[$line]++;

}

}

}



//close file

fclose($fp);



//sort chars

ksort($chars);



//print result

echo 'Sum: '.$sum.PHP_EOL;

foreach($chars as $char=>$num){

echo $char.':'.$num.PHP_EOL;

}

[mshort1985]

oh Nice, I didn’t know about the is_numeric() function :) yay learned something hehe. both are good solutions.

[_monty]

Try this…

<?php
$file_contents = trim(file_get_contents(‘/full/path/to/file.txt’));

if($file_contents)
{
$sum = 0;
$alpha_count_arr = array();
$contents_to_arr = array_map(‘trim’,array_filter(explode(“\n”, $file_contents)));

foreach ($contents_to_arr as $key => $value)
{

if(is_numeric($value))
{
$sum += $value;
}
elseif(ctype_alpha($value))
{
if(!isset($alpha_count_arr[$value]))
{
$alpha_count_arr[$value] = 1;
}
else
{
$alpha_count_arr[$value]++;
}
}

}

if(count($alpha_count_arr) > 0)
{
ksort($alpha_count_arr);
foreach ($alpha_count_arr as $character => $count)
{
echo “$character = $count<br/>”;
}
}

echo “<br/>Numeric value total: “.$sum;

}
?>

[chrisburton]

Does anyone know of a website with these mini projects for PHP?

[Taufik Nurrohman]

<?php

// Your program must read each line and
// store the data in a data structure
// of your choice.

$content = file_get_contents('numbers.txt');

$numbers = 0;
$chars = array();

$parts = explode("\n", $content);

foreach($parts as $part) {
    $part = trim($part);
    // [1]. The sum of all the individual digits.
    if(is_numeric($part)) {
        $numbers += (int) $part;
    } else {
        if($part !== "") {
            $chars[] = $part;
        }
    }
}

// [2]. How many times each character appeared in the file.
$chars = array_count_values($chars);

ksort($chars); // sort alphabetically

$str = 'Sum = ' . $numbers . "\n\n";

foreach($chars as $k => $v) {
    $str .= $k . ' = ' . $v . "\n\n";
}

echo trim($str); // output!

Demo: http://codepad.org/g2Kh9RG6

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