day 7

.aocrunner.json

@@ -95,16 +95,18 @@
     },
     {
       "part1": {
-        "solved": false,
-        "result": null,
+        "solved": true,
+        "result": "345035",
         "attempts": [],
-        "time": null
+        "time": 0.71
       },
       "part2": {
-        "solved": false,
-        "result": null,
-        "attempts": [],
-        "time": null
+        "solved": true,
+        "result": "97038163",
+        "attempts": [
+          "97038219"
+        ],
+        "time": 46.18
       }
     },
     {

README.md

@@ -17,7 +17,7 @@
 [![Day](https://badgen.net/badge/04/%E2%98%85%E2%98%85/green)](src/day04)
 [![Day](https://badgen.net/badge/05/%E2%98%85%E2%98%85/green)](src/day05)
 [![Day](https://badgen.net/badge/06/%E2%98%85%E2%98%85/green)](src/day06)
-![Day](https://badgen.net/badge/07/%E2%98%86%E2%98%86/gray)
+[![Day](https://badgen.net/badge/07/%E2%98%85%E2%98%85/green)](src/day07)
 ![Day](https://badgen.net/badge/08/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/09/%E2%98%86%E2%98%86/gray)
 ![Day](https://badgen.net/badge/10/%E2%98%86%E2%98%86/gray)
@@ -111,9 +111,9 @@ Both parts: 25.08ms
 
 ```
 Day 07
-Time part 1: -
-Time part 2: -
-Both parts: -
+Time part 1: 0.71ms
+Time part 2: 46.18ms
+Both parts: 46.89ms
 ```
 
 ```
@@ -243,8 +243,8 @@ Both parts: -
 ```
 
 ```
-Total stars: 12/50
-Total time: 331.78999999999996ms
+Total stars: 14/50
+Total time: 378.67999999999995ms
 ```
 
 <!--/RESULTS-->

src/day07/README.md

@@ -0,0 +1,9 @@
+# 🎄 Advent of Code 2021 - day 7 🎄
+
+## Info
+
+Task description: [link](https://adventofcode.com/2021/day/7)
+
+## Notes
+
+...

src/day07/index.js

@@ -0,0 +1,42 @@
+import run from "aocrunner"
+
+const parseInput = (rawInput) =>
+  rawInput.trim().split`,`.map((x) => +x).sort((a, b) => a - b)
+
+const part1 = (rawInput) => {
+  const input = parseInput(rawInput)
+  const median = input[Math.floor(input.length / 2)]
+  return input.reduce((acc, cur) => acc + Math.abs(cur - median), 0)
+}
+
+const part2 = (rawInput) => {
+  const input = parseInput(rawInput)
+  const min = input[0],
+    max = input[input.length - 1]
+  const gas = (position) =>
+    input.reduce(
+      (acc, cur) =>
+        acc + ((1 + Math.abs(cur - position)) * Math.abs(cur - position)) / 2,
+      0,
+    )
+  let bestGas = Infinity
+  for (let pos = min; pos <= max; pos++) {
+    const thisGas = gas(pos)
+    if (thisGas < bestGas) {
+      bestGas = thisGas
+    }
+  }
+  return bestGas
+}
+
+run({
+  part1: {
+    tests: [{ input: `16,1,2,0,4,2,7,1,2,14`, expected: 37 }],
+    solution: part1,
+  },
+  part2: {
+    tests: [{ input: `16,1,2,0,4,2,7,1,2,14`, expected: 168 }],
+    solution: part2,
+  },
+  trimTestInputs: true,
+})