From 136e5a4f0228a8a31589052722df2bf5b6495972 Mon Sep 17 00:00:00 2001
From: Avimathu <40541476+Avimathu@users.noreply.github.com>
Date: Fri, 21 Oct 2022 11:42:30 +0530
Subject: [PATCH] Trapping Rain Water (in C++)

Please add this new file for the issue that I have raised for issue #1055
---
 Trapping Rain Water | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 Trapping Rain Water

diff --git a/Trapping Rain Water b/Trapping Rain Water
new file mode 100644
index 00000000..47d09392
--- /dev/null
+++ b/Trapping Rain Water	
@@ -0,0 +1,40 @@
+#include<iostream>
+#include<vector>
+#include<algorithm>
+#include<cmath>
+using namespace std;
+
+int trap(vector<int>& heights) {
+    if(heights.size()<=2){
+        return 0;
+    }
+    vector<int> leftToRight;
+    int maxHeight = heights[0]; 
+    for(int i = 0; i < heights.size(); i++){
+        maxHeight = max(maxHeight , heights[i]);
+        leftToRight.push_back(maxHeight - heights[i]);
+    }
+    vector<int> rightToLeft;
+    maxHeight = heights[heights.size() - 1];
+    for(int i = heights.size() - 1; i >= 0; i--){
+        maxHeight = max(maxHeight , heights[i]);
+        rightToLeft.push_back(maxHeight - heights[i]);
+    }
+    reverse(rightToLeft.begin() , rightToLeft.end());
+    int ans = 0;
+    for(int i = 0; i < heights.size(); i++){
+        ans += min(leftToRight[i] , rightToLeft[i]);
+    }
+    return ans;
+}
+int main(){
+    int n;
+    cin>>n;
+    vector<int> heights(n,0);
+    for(int i=0;i<n;i++){
+        cin>>heights[i];
+    }
+    int waterTrapped=trap(heights);
+    cout<<waterTrapped;
+    return 0;
+}