From 7183b834e26a4ab1157d71bc2ddedcc0980e403a Mon Sep 17 00:00:00 2001
From: ashutosh <ashutosh.2201062cs@iiitbh.ac.in>
Date: Fri, 5 Apr 2024 18:06:40 +0530
Subject: [PATCH] chore: solved hard day 13 task

---
 medium/day_13/solution.cpp | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/medium/day_13/solution.cpp b/medium/day_13/solution.cpp
index 8d3ad8d..f319f79 100644
--- a/medium/day_13/solution.cpp
+++ b/medium/day_13/solution.cpp
@@ -1 +1,32 @@
-//write your code here
\ No newline at end of file
+//write your code here
+
+
+#include <iostream>
+using namespace std;
+long long int a[1000002]={0};
+int main() {
+    // cout<<5;
+    long long int n;
+    cin>>n;
+    long long int mod=1000000007;
+
+    long long int i,s;
+    s=0;
+    a[0]=0;
+    a[1]=1;
+    a[2]=2;
+    s=3;
+    for(i=3;i<=n;i++)
+    {
+        a[i]=(a[i]+a[i-1]+1)%mod;
+        s=(s+a[i])%mod;
+        a[i]=(a[i]+a[i-2])%mod;
+    }
+    if(n==1)
+    cout<<1;
+    else if(n==2)
+    cout<<3;
+    else
+    cout<<s;
+        return 0;
+}
\ No newline at end of file