Task 02

src/2020-day-03.ts

@@ -23,13 +23,13 @@ let tasksResults: any[] = ['N/A', 'N/A'];
 
 describe('Day 02', () => {
     let sample = example.split('\n');
-    let m = (sample.length * 3) / sample[0].length;
+    let m = neededPanels(3, sample);
     let input: string[];
     let panels: number;
     before(() => {
         input = readFileSync('./input/2020-day-03.txt', 'utf-8')
             .split('\n');
-            panels = (input.length * 3) / input[0].length;
+            panels = neededPanels(3, input);
     })
     describe('task01', () => {
         it('find a safe location', () => {
@@ -40,41 +40,67 @@ describe('Day 02', () => {
         })
         it('Calculate', () => {
             assert.strictEqual(task01(m, sample), 7);
+            assert.strictEqual(task01(panels, input), 171);
             tasksResults[0] = task01(panels, input)
         });
     });
     describe('test02', () => {
         it('Calculate', () => {
-            // assert.strictEqual(task02(input), 0);
-            // tasksResults[1] = task02(input);
+
+            assert.strictEqual(task02(1, 3, input), 171);
+            assert.strictEqual(task02(2, 1, sample), 2);
+            let slopes = [
+                task02(1, 1, input),
+                task02(1, 3, input),
+                task02(1, 5, input),
+                task02(1, 7, input),
+                task02(2, 1, input),
+            ];
+            assert.strictEqual(slopes[1], 171);
+            tasksResults[1] = slopes.reduce((t, c) => {
+                console.log(c, t);
+                return t *= c
+            }, 1);
         });
     });
+    it('mark', () => {
+        
+        task02(2, 1, input);
+    });
     after(() => {
         console.log('\ntask 01:', tasksResults[0]);
         console.log('\ntask 02:', tasksResults[1]);
     });
 });
 
-function task01(m: number, input: string[]): number {
-    let dist = 3;
+function task01(panels: number, input: string[], down: number = 1, right: number = 3): number {
     let trees = 0;
-    input.forEach((row: string, i: number) => {
-        trees += isTreeLocation(m, dist*i, row) ? 1 : 0;
-    });
+    for (let i = 0; i < input.length; i++) {
+        let d = i * down;
+        let r = i * right;
+        if (input[d]) {
+            trees += isTreeLocation(panels, r, input[d]) ? 1 : 0;
+        }
+    }
     return trees;
 }
 
-// function task02(input: number[]): number {
-//     return task01(input);    
-// }
+function task02(right: number, down: number, input: string[]): number {
+    return task01(neededPanels(down, input), input, right, down);    
+}
 
+function neededPanels(y: number, i:string[]) {
+    return Math.ceil(i.length * y / i[0].length);
+}
 
-
-function isTreeLocation(m: number, col: number, pattern: string): boolean {
+function isTreeLocation(panels: number, col: number, pattern: string): boolean {
     let c = pattern;
     
-    for (let i = 0; i < m; i++) {
+    for (let i = 0; i < panels; i++) {
         c += pattern;
     }
+    // if (c.charAt(col) === '#') {
+    //     console.log(c.substr(0, col) + 'X' + c.substr(col + 1));
+    // }
     return c.charAt(col) === '#';
 }