Merge pull request #470 from Kaustubh251002/kaustubh

Added Trapping Rainwater problem to Java_Problems; Added name to contributors.html

Contributors.html

@@ -583,10 +583,13 @@
 <a class="box-item" href="https://github.com/a-ayush19"><span>Ayush Awasthi</span></a>
 <a class="box-item" href="https://github.com/SamarthSawhney"><spann>Samarth Sawhney</span></a>
 <a class="box-item" href="https://github.com/highflyer910"><span>Thea M.</span></a>
+
 <a class="box-item" href="https://github.com/nyctonio"><span>Ritesh Kumar</span></a>
 <a class="box-item" href="https://github.com/geeky01adarsh"><span>Adarsh Navneet Sinha</span></a>
 <a class="box-item" href="https://github.com/RAJASETHI"><span>Raja Sethi</span></a>
     <a class="box-item" href="https://github.com/PrajaktaSathe"><span>Prajakta Sathe</span></a>
+    <a class="box-item" href="https://github.com/Kaustubh251002"><span>Kaustubh Mishra</span></a>
+
 
 
 

Program's_Contributed_By_Contributors/Java_Programs/Trappingwater.java

@@ -0,0 +1,44 @@
+package gfg_practice;
+import java.io.*;
+import java.util.*;
+import java.lang.*;
+class Trappingwater{
+    static long trappingWater(int arr[], int n) { 
+        int left[]=new int[n];
+        int right[]=new int[n];
+        left[0]=0;
+        right[n-1]=0;
+        int leftmax=0;
+        int rightmax=0;
+        for(int i=1;i<n;i++){
+            if(arr[i-1]>leftmax)
+                leftmax=arr[i-1];
+            left[i]=leftmax;
+        }
+        for(int i=n-2;i>=0;i--){
+            if(arr[i+1]>rightmax)
+                rightmax=arr[i+1];
+            right[i]=rightmax;
+        }
+        long amount=0;
+        for(int i=1;i<n-1;i++){
+            int trapped_water= Math.min(left[i],right[i])-arr[i];
+            if(trapped_water>0)
+                amount+=trapped_water;
+        }
+        return amount;
+    } 
+	public static void main(String args[]) throws IOException {
+		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+		int t=Integer.parseInt(br.readLine().trim());// for inputting the testcases
+		while(t-->0) {
+			int n=Integer.parseInt(br.readLine().trim());
+			int arr[]=new int[n];
+			String inputLine[]=br.readLine().trim().split(" ");
+			for(int i=0;i<n;i++) {
+				arr[i]=Integer.parseInt(inputLine[i]);
+			}
+			System.out.println(trappingWater(arr,n));
+		}
+	}
+}