Use underscore, dash was for Termux.

spare_change.php

@@ -0,0 +1,67 @@
+#!/usr/bin/php
+<?php
+/* 2024-03-24 Hyperling
+// Calculate the optimal amount of spare change to keep
+// at any one time which can make any cent value.
+*/
+
+echo "Got any spare change?\n";
+
+$pennies = 0; $nickels = 0; $dimes = 0; $quarters = 0;
+$maxPennies = 0; $maxNickels = 0; $maxDimes = 0; $maxQuarters = 0;
+
+for ($change = 1; $change < 100; $change++) {
+	$quarters = floor($change / 25);
+	$remainder = $change % 25;
+
+	$dimes = floor($remainder / 10);
+	$remainder = $remainder % 10;
+
+	$nickels = floor($remainder / 5);
+	$remainder = $remainder % 5;
+
+	$pennies = $remainder;
+
+	if ($quarters > $maxQuarters) {
+		$maxQuarters = $quarters;
+		echo "Amount '{$change}c' required adding another quarter, " .
+		"now need '$maxQuarters'.\n"
+		;
+	}
+	if ($dimes > $maxDimes) {
+		$maxDimes = $dimes;
+		echo "Amount '{$change}c' required adding another dime, " .
+		"now need '$maxDimes'.\n"
+		;
+	}
+	if ($nickels > $maxNickels) {
+		$maxNickels = $nickels;
+		echo "Amount '{$change}c' required adding another nickel, " .
+		"now need '$maxNickels'.\n"
+		;
+	}
+	if ($pennies > $maxPennies) {
+		$maxPennies = $pennies;
+		echo "Amount '{$change}c' required adding another penny, " .
+			"now need '$maxPennies'.\n"
+		;
+	}
+}
+
+echo "You can pay any cent value with exact change if you have " .
+	"$maxQuarters quarter(s), $maxDimes dime(s), " .
+	"$maxNickels nickel(s), and $maxPennies penn(y,ies).\n"
+;
+
+$quarters = $maxQuarters * 25;
+$dimes = $maxDimes * 10;
+$nickels = $maxNickels * 5;
+$pennies = $maxPennies;
+
+$change = $quarters + $dimes + $nickels + $pennies;
+
+echo "That means you only ever need to carry {$change}c " .
+	"unless going to multiple locations in one trip.\n"
+;
+
+exit(0);