day 2

2024/2.1.ts

@@ -0,0 +1,30 @@
+import { open } from 'node:fs/promises';
+
+
+const file = await open('./2024/inputs/2');
+const all_diffs = []
+for await (const line of file.readLines()) {
+    const levelsMatch = line.matchAll(/\d+ ?/gm)
+    const levels = Array.from(levelsMatch).map(e => Number(e[0]))
+    let previous = levels.shift()!
+    all_diffs.push(levels.map((e) => {
+        const value = e - previous
+        previous = e
+        return value
+    }))
+
+}
+const result = all_diffs.reduce((prev, line, index) => {
+    if (line.some(e => e == 0)) {
+        return prev
+    }
+    if (!line.every(e => e < 0) && !line.every(e => e > 0)) {
+        return prev
+    }
+    if (!line.every(e => Math.abs(e) >= 1 && Math.abs(e) <= 3)) {
+        return prev
+    }
+    return prev + 1
+}, 0)
+console.log(result)
+all_diffs

2024/2.2.ts

@@ -0,0 +1,54 @@
+// Doesn't works
+import { open } from 'node:fs/promises';
+
+
+const file = await open('./2024/inputs/2');
+const all_diffs = []
+const orig_lines: number[][] = []
+for await (const line of file.readLines()) {
+    const levelsMatch = line.matchAll(/\d+ ?/gm)
+    const levels = Array.from(levelsMatch).map(e => Number(e[0]))
+    all_diffs.push(compute_diff(levels))
+    orig_lines.push(levels)
+}
+
+function compute_diff(line: number[]) {
+    line = Array.from(line)
+    let previous = line.shift()!
+    return line.map((e) => {
+        const value = e - previous
+        previous = e
+        return value
+    })
+}
+function keep_only_errors(line: number[]) {
+    return line.reduce<number[]>((prev, curr, index) => {
+        if (curr == 0) {
+            prev.push(index)
+        } else if (index > 0 && (line[index - 1] < 0) && (curr > 0)) {
+            prev.push(index)
+        } else if (index > 0 && (line[index - 1] > 0) && (curr < 0)) {
+            prev.push(index)
+        } else if (!((Math.abs(curr) >= 1) && (Math.abs(curr) <= 3))) {
+            prev.push(index)
+        }
+        return prev
+    }, [])
+}
+
+const result = all_diffs.map((line) => {
+    return keep_only_errors(line)
+})
+
+const orig_lines_spliced = all_diffs.map((line, index) => {
+    const l = Array.from(orig_lines[index])
+    const errors_indexes = keep_only_errors(line)
+    if (errors_indexes.length > 0) {
+        l.splice(errors_indexes[0], 1)
+    }
+    return l
+})
+
+
+console.log(orig_lines_spliced.map(compute_diff).map(keep_only_errors).reduce((t, c) => c.length == 0 ? t + 1 : t, 0))
+all_diffs

2024/inputs/2.example

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+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9