day 12

2022/12.input

@@ -0,0 +1,41 @@
+abccccccccaaaaaaaccaaaaaaaaaaaaaaaaccccccccccccccccccccccccccccccccccccaaaaaa
+abccccccccaaaaaaaccaaaaaaaaaaaaaaaaccccccccccccccccccccccccccccccccccccaaaaaa
+abccccccccccaaaaaaccaaaaaaaaaaaaaaaaccccccccccccccccacccccccccccccccccccaaaaa
+abcccccaaaacaaaaaaccaaaaaaaaaaaaaaaaacccccccccccccccaaaccccaccccccccccccccaaa
+abccccaaaaacaaccccccaaaaaacaaacaacaaaaaaacccccccccccaaaacccaacccccccccccccaaa
+abaaccaaaaaaccccaaacaaaacacaaacaaccaaaaaacccccccccccaklaccccccccccccccccccaac
+abaaccaaaaaaccaaaaaacccccccaaacccaaaaaaaccccccccccckkkllllccccccccccccccccccc
+abaaccaaaaaaccaaaaaacccccccaaaaacaaaaaaacccccccccckkkklllllcccccccaaaccaccccc
+abacccccaacccccaaaaacccccccaaaaaccaaaaaaacccccccckkkkpppllllccccccaaaaaaccccc
+abacccccccccccaaaaacccccccccaaaacccaaaaaaccccccckkkkpppppplllccccddddaaaccccc
+abccccccccccccaaaaaccccccccccaaaccaaaccccccccccckkkppppppppllllldddddddaccccc
+abccacccccccccccccccccccccccccccccaaccccccccccckkkopppupppplllmmmmdddddaacccc
+abccaaacaaaccccccccccccccccccccaaaaaaaaccccccckkkkopuuuuupppllmmmmmmddddacccc
+abccaaaaaaaccccccccccccccccccccaaaaaaaacccccjjkkkooouuuuuuppqqqqqmmmmddddcccc
+abccaaaaaacccccccccccccccaaccccccaaaacccccjjjjjjoooouuxuuuppqqqqqqmmmmdddcccc
+abcaaaaaaaacccccccccccccaaacccccaaaaaccccjjjjoooooouuuxxuuvvvvvqqqqmmmdddcccc
+abaaaaaaaaaacccccccaaaaaaacaacccaacaaacccjjjooooouuuuxxxxvvvvvvvqqqmmmdddcccc
+abaaaaaaaaaacccaaacaaaaaaaaaacccacccaaccjjjooootttuuuxxxyyvyyvvvqqqmmmeeecccc
+abcccaaacaaacccaaaaaaacaaaaaccccccccccccjjjooottttxxxxxxyyyyyyvvqqqmmmeeccccc
+abcccaaacccccccaaaaaacaaaaaccccaaccaacccjjjnnntttxxxxxxxyyyyyvvvqqqnneeeccccc
+SbccccaacccccccaaaaaaaaacaaacccaaaaaacccjjjnnntttxxxEzzzzyyyyvvqqqnnneeeccccc
+abcccccccccccccaaaaaaaaacaaccccaaaaaccccjjjnnnttttxxxxyyyyyvvvrrrnnneeecccccc
+abcccaacccccccaaaaaaaaaccccccccaaaaaacccciiinnnttttxxxyyyyywvvrrrnnneeecccccc
+abcccaaaaaaccaaaaaaaacccccccccaaaaaaaaccciiiinnnttttxyyywyyywvrrrnnneeecccccc
+abcccaaaaaaccaaaaaaaacccccccccaaaaaaaacccciiinnnntttxwywwyyywwwrrnnneeecccccc
+abcaaaaaaaccaaaaaaaaaccccccccccccaacccccccciiinnnttwwwwwwwwwwwwrrnnneeecccccc
+abcaaaaaaaccaaaaaacccccccccccccccaaccccccaaiiiinnttwwwwwwwwwwwrrrnnnffecccccc
+abcccaaaaaaccaaaaaccccccccccccccccccccaaaaaciiinnssswwwssssrwwrrrnnnfffcccccc
+abaacaaccaaccaaaccccccccaacccccccccccccaaaaaiiinnssssssssssrrrrrronnfffcccccc
+abaccaaccaacccccccccaaacaacccccccccccccaaaaaiiimmmssssssmoosrrrrooonffaaacccc
+abaaaccccaaaaaaccccccaaaaaccccccccccccaaaaaccihmmmmsssmmmoooooooooofffaaacccc
+abaaaccccaaaaaacccccccaaaaaacccccccccccccaacchhhmmmmmmmmmoooooooooffffaaccccc
+abaacccaaaaaaaccccccaaaaaaaaccccaaccccccccccchhhhmmmmmmmgggggooofffffaaaccccc
+abaacccaaaaaaaccccccaaaaaaaccccaaaaccccccccccchhhhmmmmhggggggggfffffaaaaccccc
+abccccccaaaaaaacccccaacaaaaacccaaaaccccccccccchhhhhhhhggggggggggfffaacaaccccc
+abccaacccaaaaaaccccccccaaaaaccaaaaacccccccccccchhhhhhhggaaaaaaccccccccccccccc
+abccaaaccaaccccccccccccccaaaaaaaaaccccccccccccccchhhhaaaccaaaacccccccccccccaa
+abaaaaaaaccccccccccccccccaaaaaaaaccccccccccccccccccccaaaccccaaccccccccccccaaa
+abaaaaaaaccccccccaaaccccacaaaaaacccccccccccccccccccccaaaccccccccccccccccccaaa
+abaaaaaacccccccaaaaacaaaaaaaaaaacccccccccccccccccccccaaccccccccccccccccaaaaaa
+abaaaaaacccccccaaaaaaaaaaaaaaaaaaacccccccccccccccccccccccccccccccccccccaaaaaa

2022/12.js

@@ -0,0 +1,71 @@
+const fs = require('fs');
+const map = fs.readFileSync('12.input').toString().split('\n').map(s => s.split(''));
+
+const [rows, cols] = [map.length, map[0].length - 1];
+const traverseDirections = [[-1, 0], [1, 0], [0, -1], [0, 1]];
+
+const isInMap = ([row, col]) => row >= 0 && row < rows && col >= 0 && col < cols ;
+const bfsCost = currElevation => ([row, col]) => map[row][col].charCodeAt(0) - currElevation.charCodeAt(0) <= 1;
+
+const BreadthFirst = (start, end) => {
+    const viewQueue = [[start, 0]];
+    const visited = new Set([JSON.stringify(start)]);
+    let result = Infinity;
+
+    while (viewQueue.length != 0) {
+        const [pos, views] = viewQueue.shift();
+        
+        if (JSON.stringify(pos) == JSON.stringify(end)) {
+            result = views;
+            break;
+        }
+        
+        // Map, so make new array for each up & right direction
+        traverseDirections.map(([up, right]) => [pos[0] + up, pos[1] + right])
+                          // Can we actually move there?
+                          .filter(isInMap)
+                          // Can we climb there?
+                          .filter(bfsCost(map[pos[0]][pos[1]]))
+                          // Have we seen this before?
+                          .filter(pos => !visited.has(JSON.stringify(pos)))
+                          // OK, add next in direction to view queue
+                          .forEach(pos => {
+                                visited.add(JSON.stringify(pos));
+                                viewQueue.push([pos, views + 1]);
+                          });
+    }
+
+    return result;
+}
+
+const partOne = () => {
+    let start, end;
+    for (let row = 0; row < rows; row++)
+    for (let col = 0; col < cols; col++) {
+        if (map[row][col] == 'S') { start = [row, col]; map[row][col] = "a"; }
+        if (map[row][col] == 'E') { end = [row, col]; map[row][col] = "z"; }
+    }
+
+    const ret = BreadthFirst(start, end);
+    map[end[0]][end[1]] = 'E';
+    return ret;
+}
+
+const partTwo = () => {
+    const starting = [];
+    let end;
+    for (let row = 0; row < rows; row++)
+    for (let col = 0; col < cols; col++) {
+        if (map[row][col] == 'a') { starting.push([row, col]) }
+        if (map[row][col] == 'E') { end = [row, col]; map[row][col] = "z"; }
+    }
+
+    const candidates = [];
+    for (const start of starting)
+        candidates.push(BreadthFirst(start, end));
+
+    return candidates.sort((a, b) => a - b)[0];
+}
+
+console.log(`Part 1: ${partOne()}`);
+console.log(`Part 2: ${partTwo()}`);