Maximum profit earned by buying and selling shares

EASY

Given a list containing future prediction of share prices, find maximum profit that can be earned by buying and selling shares any number of times with constraint that a new transaction can only start after previous transaction is complete.

Example #1

Input

1 3 2 1 7

Output

Solution

<?php
$prices = explode(' ', trim(fgets(STDIN)));

$count = count($prices);
$profit = 0;
for ($i = 1; $i < $count; $i++) {
    if ($prices[$i] > $prices[$i-1]) {
        $profit += $prices[$i] - $prices[$i-1];
    }
}
echo $profit;

Tests

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