feat: solve new question

Author: arwildo

trapping-rain-water/main.js

@@ -0,0 +1,32 @@
+/**
+ * @param {number[]} height
+ * @return {number}
+ */
+var trap = function(height) {
+    let max_l = 0;
+    let max_r = 0;
+    let body_water_count = 0; 
+
+    let l = 0;
+    let r = height.length - 1;
+    
+    while (l < r) {
+        if (height[l] < height[r]) {
+            if(height[l] > max_l) {
+                max_l = height[l];
+            } else {
+                body_water_count += (max_l - height[l]);
+            }
+            l++;
+        } else {
+            if(height[r] > max_r) {
+                max_r = height[r];
+            } else {
+                body_water_count += (max_r - height[r]);
+            }
+            r--;
+        }
+    }
+
+    return body_water_count;
+};