refactoring

2021/09/part2.mjs

@@ -2,7 +2,7 @@ import fs from "fs-extra";
 import fp from "lodash/fp.js";
 import _ from "lodash";
 
-import * as p1 from './part1.mjs';
+import * as p1 from "./part1.mjs";
 
 function getBasinSize([x, y], grid, seen) {
     if (seen[x][y]) return 0;
@@ -10,35 +10,27 @@ function getBasinSize( [x,y], grid, seen ) {
     seen[x][y] = true;
 
     if (grid[x][y] == 9) return 0;
-    let size = 1;
 
     const neighbours = p1.genNeighbours(grid.length, grid[0].length);
-    const coords = p1.genCoords(grid);
 
-    neighbours(x,y).map( n => getBasinSize(n,grid,seen) ).forEach(
-        x => size+=x
-    );
-
-    return size;
+    return _.sum([
+        1,
+        ...neighbours(x, y).map((n) => getBasinSize(n, grid, seen)),
+    ]);
 }
 
 export function solution(grid) {
     const seen = grid.map(() => []);
     let basinSizes = [];
 
-
     for (const x of _.range(grid.length)) {
         for (const y of _.range(grid[x].length)) {
-            if( seen[x][y] ) continue;
-
-            if( grid[x][y] == 9 ) {
-                seen[x][y] = true;
-                continue;
-            }
             basinSizes.push(getBasinSize([x, y], grid, seen));
         }
     }
 
-    basinSizes.sort( (a,b) => a < b ? 1 : -1 );
-    return basinSizes.splice(0,3).reduce( (a,b) => a*b ) ;
+    return basinSizes
+        .sort((a, b) => (a > b ? 1 : -1))
+        .splice(-3)
+        .reduce(_.multiply);
 }