hsegnitz
diff --git a/‎php/2023/09/01.php
Lines changed: 61 additions & 0 deletions b/‎php/2023/09/01.php
Lines changed: 61 additions & 0 deletions
diff --git a/‎php/2023/09/02.php
Lines changed: 62 additions & 0 deletions b/‎php/2023/09/02.php
Lines changed: 62 additions & 0 deletions
diff --git a/‎php/2023/09/example.txt
68 Bytes b/‎php/2023/09/example.txt
68 Bytes
diff --git a/‎php/2023/09/input.txt
20.9 KB b/‎php/2023/09/input.txt
20.9 KB
@@ -0,0 +1,61 @@
+<?php
+
+namespace Year2023\Day08;
+
+$start = microtime(true);
+
+#$lines = file('example.txt', FILE_IGNORE_NEW_LINES);
+$lines = file('input.txt', FILE_IGNORE_NEW_LINES);
+
+$seqs = [];
+foreach ($lines as $line) {
+    $seqs[] = explode(" ", $line);
+}
+
+
+
+function findNextInSequence (array $in): int
+{
+    $dims[] = $newLine = $in;
+    while (!isAllZeros($newLine)) {
+        $dims[] = $newLine = getNextRow($newLine);
+    }
+
+    for ($i = count($dims)-1; $i > 0; $i--) {
+        $dims[$i-1][] = $dims[$i-1][array_key_last($dims[$i-1])] + $dims[$i][array_key_last($dims[$i])];
+    }
+
+#    print_r($dims);
+
+    return $dims[0][array_key_last($dims[0])];
+}
+
+function getNextRow(array $in): array
+{
+    $next = [];
+    for ($i = 0, $count = count($in); $i < $count-1; $i++) {
+        $next[] = $in[$i+1] - $in[$i];
+    }
+    return $next;
+}
+
+function isAllZeros(array $in): bool
+{
+    foreach ($in as $i) {
+        if ($i !== 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+$sum = 0;
+foreach ($seqs as $seq) {
+    $sum += findNextInSequence($seq);
+}
+
+echo "\n", $sum, "\n";
+
+echo microtime(true) - $start;
+echo "\n";
+
@@ -0,0 +1,62 @@
+<?php
+
+namespace Year2023\Day08;
+
+$start = microtime(true);
+
+#$lines = file('example.txt', FILE_IGNORE_NEW_LINES);
+$lines = file('input.txt', FILE_IGNORE_NEW_LINES);
+
+$seqs = [];
+foreach ($lines as $line) {
+    $seqs[] = explode(" ", $line);
+}
+
+
+
+function findPreviousInSequence (array $in): int
+{
+    $dims[] = $newLine = $in;
+    while (!isAllZeros($newLine)) {
+        $dims[] = $newLine = getNextRow($newLine);
+    }
+
+    for ($i = count($dims)-1; $i > 0; $i--) {
+        $dims[$i-1][] = $dims[$i-1][array_key_last($dims[$i-1])] + $dims[$i][array_key_last($dims[$i])];   // part1
+        array_unshift($dims[$i-1], $dims[$i-1][0] - $dims[$i][0]);    // part2
+    }
+
+   # print_r($dims);
+
+    return $dims[0][0];
+}
+
+function getNextRow(array $in): array
+{
+    $next = [];
+    for ($i = 0, $count = count($in); $i < $count-1; $i++) {
+        $next[] = $in[$i+1] - $in[$i];
+    }
+    return $next;
+}
+
+function isAllZeros(array $in): bool
+{
+    foreach ($in as $i) {
+        if ($i !== 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+$sum = 0;
+foreach ($seqs as $seq) {
+    $sum += findPreviousInSequence($seq);
+}
+
+echo "\n", $sum, "\n";
+
+echo microtime(true) - $start;
+echo "\n";
+