53 lines
1.1 KiB
PHP
53 lines
1.1 KiB
PHP
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<?php
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// https://adventofcode.com/2017/day/5
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function puzzle1(string $input)
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{
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$jumps = 0;
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$placement = 0;
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$instructions = array_filter(explode(PHP_EOL, $input));
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while (true) {
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// Get current jump size
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$jumpSize = $instructions[$placement];
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// Increment jump size
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$instructions[$placement]++;
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// Do jump
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$placement += $jumpSize;
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$jumps++;
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if ($placement >= count($instructions)) {
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return $jumps;
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}
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}
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}
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function puzzle2(string $input)
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{
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$jumps = 0;
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$placement = 0;
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$instructions = array_filter(explode(PHP_EOL, $input));
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while (true) {
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// Get current jump size
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$jumpSize = $instructions[$placement];
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// Update instructions
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if ($instructions[$placement] >= 3) {
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$instructions[$placement]--;
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} else {
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$instructions[$placement]++;
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}
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// Do jump
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$placement += $jumpSize;
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$jumps++;
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if ($placement >= count($instructions)) {
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return $jumps;
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}
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}
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}
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