Create RainWaterTapping.py

Author: Darkshadow9799

Dynamic Programming/RainWaterTapping.py

@@ -0,0 +1,23 @@
+# Rain water Trapping Problem
+
+def rWTP(arr):
+	left = []
+	right = []
+	n = len(arr)
+	left.append(arr[0])
+	right = [0 for i in range(n)]
+	right[n-1] = arr[n-1]
+	for i in range(1, n):
+	    left.append(max(left[i-1],arr[i]))
+	for j in range(n-2, -1, -1):
+	    right.append(max(right[j+1], arr[j]))
+	
+	ans = 0 
+	for i in range(n):
+		ans += max(left[i], right[i]) - arr[i]
+	
+	return ans
+	
+# Test 1:
+arr = [3, 1, 2, 4, 0, 1, 3, 2]
+print(rWTP(arr))