Trapping rain water file added to array folder with complexities and explanation

Author: vishvarana

Arrays/trappingrainwater.cpp

@@ -0,0 +1,28 @@
+// Given an array of numbers which are heights to the container, we need to find upto what maximum value water can be filled in this vessel
+// of different heights.
+// Time complexity - O(n)
+//Space complexity - O(1)
+#include<bits/stdc++.h>
+using namespace std;
+
+int main(){
+    int arr[]={1,8,6,2,5,4,8,3,7};
+    int l=0,n=sizeof(arr)/sizeof(int),r=n-1;
+    int max_area=0,h,a,b;
+
+    while(l<r){
+        h=min(arr[l],arr[r]);
+        b=r-l;
+        a=h*b;
+        max_area=max(a,max_area);
+        if(arr[l]<=arr[r]){
+            l++;
+        }
+        else{
+            r--;
+        }
+    }
+    cout<<"Maximum water that can be trapped is : "<<max_area;
+    return 0;
+
+}