Cin bug — Google KickStart [Help]

№	Пользователь	Рейтинг
1	tourist	3690
2	jiangly	3647
3	Benq	3581
4	orzdevinwang	3570
5	Geothermal	3569
5	cnnfls_csy	3569
7	Radewoosh	3509
8	ecnerwala	3486
9	jqdai0815	3474
10	gyh20	3447

№	Пользователь	Вклад
1	maomao90	173
2	awoo	164
3	adamant	163
4	TheScrasse	160
5	nor	157
6	maroonrk	155
7	-is-this-fft-	152
8	Petr	146
8	orz	146
10	pajenegod	145

Hello guys. Today, i was practice past Google KickStart problems. But, always that i used the cin object, all answers turn on zero.

For example, for this problem: problem link

I think the which problem do not matter. My problem is only with cin object.

Using scanf, i got ACC:

ACC code

#include <bits/stdc++.h>
using namespace std;

#define int long long

//Main
int N, M, K, L, R, J, P, CASES;
int A,B,C;

main(){
   std::ios::sync_with_stdio(false);

   scanf("%lld", &CASES);
   for(int cases = 1; cases <= CASES; cases++){
      int ans = 0;
      scanf("%lld", &N);
      vector<int> v(N);
      for(int &x: v) scanf("%lld", &x);
      for(int i = 1; i+1<N; i++){
         ans += v[i]>v[i-1] and v[i]>v[i+1];
      }
      printf("Case #%lld: %lld\n", cases, ans);
   }
}

Using object cin, works locally well, but when i submitted, i got all outputs igual to zero:

Zero outputs

#include <bits/stdc++.h>
using namespace std;

#define int long long

//Main
int N, M, K, L, R, J, P, CASES;
int A,B,C;

main(){
   std::ios::sync_with_stdio(false);
    cin.tie(0);
    
   scanf("%lld", &CASES);
   for(int cases = 1; cases <= CASES; cases++){
      int ans = 0;
      cin >> N;
      vector<int> v(N);
      for(int &x: v) cin >> x;
      for(int i = 1; i+1<N; i++){
         ans += v[i]>v[i-1] and v[i]>v[i+1];
      }
      printf("Case #%lld: %lld\n", cases, ans);
   }
}

Can anyone help me?

Thanks for your help.