PHP Exercises: Print mode values from a given a sequence of integers

Last update on April 19 2025 11:50:30 (UTC/GMT +8 hours)

60. Mode Values from Sequence

Write a PHP program to print mode values from a given a sequence of integers. The mode value is the element which occurs most frequently. If there are several mode values, print them in ascending order.

Input:A sequence of integer’s ai (1 ≤ ai ≤ 100). The number of integers is less than or equals to 100.

Sample Solution:

PHP Code:

<?php
// Initialize an empty array to store input values
$hoge = array();

// Continue reading lines from standard input until an empty line is encountered
while ($hoge[] = trim(fgets(STDIN))) {}

// Count the occurrences of each unique value in the array
$hage = array_count_values($hoge);

// Find the maximum occurrence count
$max = max($hage);

// Find the keys (values) that have the maximum occurrence count
$koge = array_keys($hage, $max);

// Output the result
echo "Mode values (in ascending order):\n";

// Sort the keys in ascending order
sort($koge, SORT_ASC);

// Iterate through the sorted keys and output each value
foreach ($koge as $val) {
    echo $val . PHP_EOL;
}

?>

Explanation:

Initialize an Empty Array:

An empty array named $hoge is initialized to store input values.

Read Input Until Empty Line:

A while loop reads lines from standard input using fgets(STDIN), trimming whitespace with trim().
Each non-empty line is added to the $hoge array.
The loop stops when an empty line is encountered.

Count Occurrences of Each Value:

The function array_count_values() is used to count the occurrences of each unique value in the $hoge array.
The result is stored in the $hage associative array, where keys are the unique values and values are their counts.

Find Maximum Occurrence Count:

The max() function is used to find the highest occurrence count from the $hage array, stored in the variable $max.

Get Keys with Maximum Occurrence:

The function array_keys() retrieves all keys (unique values) from $hage that have the occurrence count equal to $max.
The result is stored in the $koge array.

Output the Result:

A message "Mode values (in ascending order):" is printed to indicate what will be displayed next.

Sort the Keys in Ascending Order:

The sort() function is used to sort the $koge array in ascending order.

Iterate and Output Each Mode Value:

A foreach loop iterates through the sorted $koge array, printing each mode value on a new line.

Sample Input:
6
7
4
6
9
8
6
4
10
8
4
5

Sample Output:

Mode values (in ascending order):
4
6

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to calculate the mode of a list of integers and output all values that appear most frequently.
Write a PHP script to count the frequency of array elements and display the mode values in ascending order.
Write a PHP function to determine mode values in an array while handling multiple modes correctly.
Write a PHP script to filter a sequence for frequency counts and then output only the most frequent numbers sorted.

PHP Code Editor:

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