solved part 1. small mistakes with using practice instead of input and forgetting something or other. solved part 2 but forgot to update the loop iteration count and I was scrolled to the wrong part of the page so I was like "yeah, answer looks correct" but that was part 1's practice answer and then I switched to real input and it was part 1's real answer. had to wait a minute to submit. didn't miss out on the leaderboard because of that luckily, but it did put me at #250 when I'd've gotten much higher with 00:06:48. minor mistakes on part 2: forgot to update the variable and that took a bit to debug.

Author: pfgithub

2021/solutions/day6/day6.1.ts

@@ -0,0 +1,38 @@
+/*
+input: string, lines: string[], dblines: string[][]
+copy(text: string) → clipboard
+error(message: string) → thrown error
+-5..mod(3) → @mod(-5, 3)
+*/
+
+// Cardinals:
+// [[1,0],[-1,0],[0,1],[0,-1]]
+// +Diagonals:
+// [[1,0],[-1,0],[0,1],[0,-1],[-1,-1],[-1,1],[1,-1],[1,1]]
+
+export {};
+
+const practice = `3,4,3,1,2
+`;
+// input = practice;
+
+let fish = input.trim().split(",").map(w => +w);
+
+function step() {
+    let newfish: number[] = [];
+    fish = fish.flatMap(f => {
+        if(f === 0) {
+            newfish.push(8);
+            return [6];
+        }
+        return [f - 1];
+    });
+    fish = [...fish, ...newfish];
+}
+
+for(let i = 0; i < 80; i++) {
+    step();
+}
+
+fish.dwth(log);
+console.log(fish.length);

2021/solutions/day6/day6.2.ts

@@ -0,0 +1,47 @@
+/*
+input: string, lines: string[], dblines: string[][]
+copy(text: string) → clipboard
+error(message: string) → thrown error
+-5..mod(3) → @mod(-5, 3)
+*/
+
+// Cardinals:
+// [[1,0],[-1,0],[0,1],[0,-1]]
+// +Diagonals:
+// [[1,0],[-1,0],[0,1],[0,-1],[-1,-1],[-1,1],[1,-1],[1,1]]
+
+export {};
+
+const practice = `3,4,3,1,2
+`;
+// input = practice;
+
+let fish = input.trim().split(",").map(w => +w);
+
+let counts = new Array(9).fill(0);
+
+for(const fsh of fish) {
+    counts[fsh]++;
+}
+
+function step() {
+    let nc: number[] = [...counts];
+    counts.forEach((c, i) => {
+        if(i == 0) {
+            nc[i] -= c;
+            nc[6] += c;
+            nc[8] += c;
+        }else{
+            nc[i] -= c;
+            nc[i - 1] += c;
+        }
+    });
+    counts = nc;
+}
+
+for(let i = 0; i < 256; i++) {
+    step();
+}
+
+counts.dwth(log);
+console.log(counts.reduce((t, c) => t + c, 0));

2021/solutions/day6/day6.3.ts

@@ -0,0 +1,17 @@
+/*
+input: string, lines: string[], dblines: string[][]
+copy(text: string) → clipboard
+error(message: string) → thrown error
+-5..mod(3) → @mod(-5, 3)
+*/
+
+// Cardinals:
+// [[1,0],[-1,0],[0,1],[0,-1]]
+// +Diagonals:
+// [[1,0],[-1,0],[0,1],[0,-1],[-1,-1],[-1,1],[1,-1],[1,1]]
+
+export {};
+
+const practice = ``;
+
+// input = practice;

2021/solutions/day6/day6.4.ts

@@ -0,0 +1,17 @@
+/*
+input: string, lines: string[], dblines: string[][]
+copy(text: string) → clipboard
+error(message: string) → thrown error
+-5..mod(3) → @mod(-5, 3)
+*/
+
+// Cardinals:
+// [[1,0],[-1,0],[0,1],[0,-1]]
+// +Diagonals:
+// [[1,0],[-1,0],[0,1],[0,-1],[-1,-1],[-1,1],[1,-1],[1,1]]
+
+export {};
+
+const practice = ``;
+
+// input = practice;

2021/solutions/day6/day6.5.ts

@@ -0,0 +1,17 @@
+/*
+input: string, lines: string[], dblines: string[][]
+copy(text: string) → clipboard
+error(message: string) → thrown error
+-5..mod(3) → @mod(-5, 3)
+*/
+
+// Cardinals:
+// [[1,0],[-1,0],[0,1],[0,-1]]
+// +Diagonals:
+// [[1,0],[-1,0],[0,1],[0,-1],[-1,-1],[-1,1],[1,-1],[1,1]]
+
+export {};
+
+const practice = ``;
+
+// input = practice;

2021/solutions/day6/day6.txt

@@ -0,0 +1 @@
+1,5,5,1,5,1,5,3,1,3,2,4,3,4,1,1,3,5,4,4,2,1,2,1,2,1,2,1,5,2,1,5,1,2,2,1,5,5,5,1,1,1,5,1,3,4,5,1,2,2,5,5,3,4,5,4,4,1,4,5,3,4,4,5,2,4,2,2,1,3,4,3,2,3,4,1,4,4,4,5,1,3,4,2,5,4,5,3,1,4,1,1,1,2,4,2,1,5,1,4,5,3,3,4,1,1,4,3,4,1,1,1,5,4,3,5,2,4,1,1,2,3,2,4,4,3,3,5,3,1,4,5,5,4,3,3,5,1,5,3,5,2,5,1,5,5,2,3,3,1,1,2,2,4,3,1,5,1,1,3,1,4,1,2,3,5,5,1,2,3,4,3,4,1,1,5,5,3,3,4,5,1,1,4,1,4,1,3,5,5,1,4,3,1,3,5,5,5,5,5,2,2,1,2,4,1,5,3,3,5,4,5,4,1,5,1,5,1,2,5,4,5,5,3,2,2,2,5,4,4,3,3,1,4,1,2,3,1,5,4,5,3,4,1,1,2,2,1,2,5,1,1,1,5,4,5,2,1,4,4,1,1,3,3,1,3,2,1,5,2,3,4,5,3,5,4,3,1,3,5,5,5,5,2,1,1,4,2,5,1,5,1,3,4,3,5,5,1,4,3

README.md

@@ -7,12 +7,13 @@
 ### 2021
 
 Total Score: 39  
-Times On Leaderboard: 1 / 6 (~17%)  
+Times On Leaderboard: 1 / 8 (~13%)  
 Highest Leaderboard Position: 62ᵗʰ place
 Best Day was Day 2: 39 points, #178/#62
 
 | Day |     Time |  Rank | Score |     Time |  Rank | Score |
 | --: | -------: | ----: | ----: | -------: | ----: | ----: |
+|   6 | 00:03:17 |   128 |       | 00:07:48 |   250 |       |
 |   5 | 18:54:29 | 48349 |       | 18:56:16 | 45151 |       |
 |   4 | 00:09:35 |   172 |       | 00:15:19 |   273 |       |
 |   3 | 00:03:42 |   178 |       | 00:13:24 |   276 |       |