Q-42 (Day-502)

Trapping Rain Water.java

@@ -0,0 +1,22 @@
+class Solution {
+    public int trap(int[] height) {
+        int ans = 0;
+        int left = 0;
+        int right = height.length - 1;
+        while (left < right) {
+            if (height[left] <= height[right]) {
+                int current = left;
+                while (height[++left] < height[current]) {
+                    ans += height[current] - height[left];
+                } 
+            } 
+            else {
+                int current = right;
+                while (height[--right] < height[current]) {
+                    ans += height[current] - height[right];
+                }
+            }
+        }
+        return ans;
+    }
+}