✨ 42. Trapping Rain Water

src/trapping-rain-water/index.js

@@ -2,36 +2,39 @@
  * @param {number[]} height
  * @return {number}
  */
-var trap = function(height) {
-  const leftMaxList = getMaxList(height, 1)
-  const rightMaxList = getMaxList(height, -1)
-  const sum = height.reduce((total, h, index) => total += getWater(h, leftMaxList[index], rightMaxList[index]), 0)
+let trap = function(height) {
+  const leftMaxList = getMaxList(height, 1);
+  const rightMaxList = getMaxList(height, -1);
+  const sum = height.reduce(
+      (total, h, index) =>
+        (total += getWater(h, leftMaxList[index], rightMaxList[index])),
+      0
+  );
   return sum;
 };
 
-
 const getMaxList = (_height, position) => {
   const height = _height.slice();
   if (position < 0) {
-      height.reverse();
+    height.reverse();
   }
   const list = [height[0]];
   for (let i = 1, len = height.length; i < len; i++) {
-      if (height[i] > list[i - 1]) {
-          list[i] = height[i]
-      } else {
-          list[i] = list[i - 1]
-      }
+    if (height[i] > list[i - 1]) {
+      list[i] = height[i];
+    } else {
+      list[i] = list[i - 1];
+    }
   }
   if (position < 0) {
-      list.reverse();
+    list.reverse();
   }
   return list;
-}
+};
 
 const getWater = (h, leftMax, rightMax) => {
   const value = Math.max(Math.min(leftMax, rightMax) - h, 0);
   return value;
-}
+};
 
 export default trap;

src/trapping-rain-water/index.test.js

@@ -2,9 +2,9 @@ import trap from './';
 
 describe('42. Trapping Rain Water:', () => {
   test('Example 1', () => {
-    expect(trap([0,1,0,2,1,0,1,3,2,1,2,1])).toBe(6);
+    expect(trap([0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1])).toBe(6);
   });
   test('Example 2', () => {
-    expect(trap([4,2,0,3,2,5])).toBe(9);
+    expect(trap([4, 2, 0, 3, 2, 5])).toBe(9);
   });
 });