[JS][6kyu] Find an area

codewars/6kyu/find-an-area/koronya.js

@@ -0,0 +1,41 @@
+// [JS][6kyu] Find an area
+// find-an-area
+// https://www.codewars.com/kata/59b166f0a35510270800018d/train/javascript
+
+class Point {
+  #x
+  #y
+
+  get x() {
+    return this.#x
+  }
+  get y() {
+    return this.#y
+  }
+
+  constructor(x, y) {
+    this.#x = x
+    this.#y = y
+  }
+}
+
+function findArea(points) {
+  const limit = points.length - 1
+  let result = 0
+  for (let i = 0; i < limit; i += 1 || 0) {
+    const [x1, y1] = [points[i].x, points[i].y]
+    const [x2, y2] = [points[i + 1].x, points[i + 1].y]
+    const belowY = Math.min(y1, y2)
+    const triangleArea = ((x2 - x1) * Math.abs(y2 - y1)) / 2
+    const squareArea = (x2 - x1) * belowY
+    result += triangleArea + squareArea
+  }
+
+  return result
+}
+
+findArea([new Point(0, 0), new Point(1, 4), new Point(3, 2)]) === 8
+findArea([new Point(-3, 0), new Point(-1, 4), new Point(3, 2)]) === 16
+findArea([new Point(-3, 2), new Point(-1, 0), new Point(3, 2)]) === 6
+findArea([new Point(-3, 2), new Point(3, 5)]) === 21
+findArea([new Point(-3, 2), new Point(-1, 5), new Point(0, 3), new Point(3, 7), new Point(4, 6)]) === 32.5