From eac2a1ea0a83f97dd5d1772583d6299cfb8619c1 Mon Sep 17 00:00:00 2001
From: Mohd Rizwan <105350689+rizwanmoha@users.noreply.github.com>
Date: Fri, 21 Oct 2022 23:46:31 +0530
Subject: [PATCH] Codeforces - All are Same

Question based on math and number theory
---
 All_are_Same.cpp | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 All_are_Same.cpp

diff --git a/All_are_Same.cpp b/All_are_Same.cpp
new file mode 100644
index 0000000..7774757
--- /dev/null
+++ b/All_are_Same.cpp
@@ -0,0 +1,44 @@
+#include <iostream>
+   #include<bits/stdc++.h>
+   using namespace std;
+  
+  int gcd(int a, int b)
+{
+   
+    if (a == 0)
+       return b;
+    if (b == 0)
+       return a;
+  
+    
+    if (a == b)
+        return a;
+  
+    
+    if (a > b)
+        return gcd(a-b, b);
+    return gcd(a, b-a);
+}
+int main(){
+    int t;
+    cin>>t;
+    while(t--){
+        int n ;
+        cin>>n;
+        int arr[n];
+        for(int i=0;i<n;i++){
+            cin>>arr[i];
+        }
+        int ans = abs(arr[0] - arr[1]);
+        for(int i=1;i<n-1;i++){
+           ans = gcd(ans , abs(arr[i] - arr[i+1]));
+            
+        }
+        if(ans ==0){
+            cout<<-1<<endl;
+        }
+        else{
+            cout<<ans<<endl;
+        }
+    }
+}