Problem p02596 (C++)

Buggy submission (status: Time Limit Exceeded):
/*
Author : Chandan Agrawal
College : Poornima College of Engg. jaipur, Raj
Mail : chandanagrawal23@gmail.com


" when you are not practicing someone else is ,
 and the day u meet them u will lose "

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

#define fastio                                                                 \
  ios_base::sync_with_stdio(false);                                            \
  cin.tie(0);                                                                  \
  cout.tie(0);
#define MAX 200050

#define ll long long
#define ld long double
#define lli long long int

#define pb push_back
#define INF 1000000000000
#define mod 1000000007

// trignometric function always give value in Radians only
#define PI acos(-1) // 3.1415926535897932384626433832795028
#define dsin(degree) sin(degree *(PI / 180.0))
#define dcos(degree) cos(degree *(PI / 180.0))
#define dtan(degree) tan(degree *(PI / 180.0))

#define rsin(radian) sin(radian)
#define rcos(radian) cos(radian)
#define rtan(radian) tan(radian)

#define mem0(a) memset(a, 0, sizeof(a))
#define mem1(a) memset(a, -1, sizeof(a))

#define loop(i, n) for (lli i = 0; i < n; i++)
#define FOR(i, a, b) for (lli i = a; i < b; i += 1)

#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define sz(x) int(x.size())
#define F first
#define S second

#define mii map<lli, lli>
#define mci map<char, lli>
#define vi vector<lli>
#define vbool vector<bool>
#define seti set<lli>
#define pii pair<lli, lli>
#define pcc pair<char, char>

#define gcd(a, b) __gcd((a), (b))
#define lcm(a, b) (a / gcd(a, b)) * b
#define abs(x) ((x < 0) ? -(x) : x)

#define endl '\n'

template <typename T> void print(T x) { cout << x << endl; }
template <typename T1, typename T2> void print2(T1 x, T2 y) {
  cout << x << " " << y << endl;
}
template <typename T1, typename T2, typename T3> void print3(T1 x, T2 y, T3 z) {
  cout << x << " " << y << " " << z << endl;
}

#define scanarr(a, n)                                                          \
  for (lli i = 0; i < n; i++)                                                  \
    cin >> a[i];
#define scanvec(a, n)                                                          \
  for (lli i = 0; i < n; i++) {                                                \
    lli x;                                                                     \
    cin >> x;                                                                  \
    a.pb(x);                                                                   \
  }

#define printarr(a, n)                                                         \
  for (lli i = 0; i < n; i++)                                                  \
    cout << a[i] << " ";                                                       \
  cout << endl;
#define printvec(vec)                                                          \
  for (auto xt : vec)                                                          \
    cout << xt << " ";                                                         \
  cout << "\n";

#define FD(N) fixed << setprecision(N)

#define deb(x) cout << #x << " " << x << endl;

// chandan1,2
void chandan1() {
  int y = 1;
  return;
}
void chandan2() {
  loop(i, 10) { lli x = 1; }
  return (chandan1());
}

int main() {
  fastio lli t = 1;
  // cin>>t;
  chandan2();
  while (t--) {
    lli k;
    cin >> k;
    if (k % 2 == 0)
      print(-1);
    else {
      lli ans = 0;
      lli cnt = 0;
      while (true) {
        ans = ans * 10 + 7;
        ans %= k;
        cnt++;
        if (ans == 0)
          break;
      }
      print(cnt);
    }
  }
  return 0;
}


Fixed submission:
/*
Author : Chandan Agrawal
College : Poornima College of Engg. jaipur, Raj
Mail : chandanagrawal23@gmail.com


" when you are not practicing someone else is ,
 and the day u meet them u will lose "

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

#define fastio                                                                 \
  ios_base::sync_with_stdio(false);                                            \
  cin.tie(0);                                                                  \
  cout.tie(0);
#define MAX 200050

#define ll long long
#define ld long double
#define lli long long int

#define pb push_back
#define INF 1000000000000
#define mod 1000000007

// trignometric function always give value in Radians only
#define PI acos(-1) // 3.1415926535897932384626433832795028
#define dsin(degree) sin(degree *(PI / 180.0))
#define dcos(degree) cos(degree *(PI / 180.0))
#define dtan(degree) tan(degree *(PI / 180.0))

#define rsin(radian) sin(radian)
#define rcos(radian) cos(radian)
#define rtan(radian) tan(radian)

#define mem0(a) memset(a, 0, sizeof(a))
#define mem1(a) memset(a, -1, sizeof(a))

#define loop(i, n) for (lli i = 0; i < n; i++)
#define FOR(i, a, b) for (lli i = a; i < b; i += 1)

#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define sz(x) int(x.size())
#define F first
#define S second

#define mii map<lli, lli>
#define mci map<char, lli>
#define vi vector<lli>
#define vbool vector<bool>
#define seti set<lli>
#define pii pair<lli, lli>
#define pcc pair<char, char>

#define gcd(a, b) __gcd((a), (b))
#define lcm(a, b) (a / gcd(a, b)) * b
#define abs(x) ((x < 0) ? -(x) : x)

#define endl '\n'

template <typename T> void print(T x) { cout << x << endl; }
template <typename T1, typename T2> void print2(T1 x, T2 y) {
  cout << x << " " << y << endl;
}
template <typename T1, typename T2, typename T3> void print3(T1 x, T2 y, T3 z) {
  cout << x << " " << y << " " << z << endl;
}

#define scanarr(a, n)                                                          \
  for (lli i = 0; i < n; i++)                                                  \
    cin >> a[i];
#define scanvec(a, n)                                                          \
  for (lli i = 0; i < n; i++) {                                                \
    lli x;                                                                     \
    cin >> x;                                                                  \
    a.pb(x);                                                                   \
  }

#define printarr(a, n)                                                         \
  for (lli i = 0; i < n; i++)                                                  \
    cout << a[i] << " ";                                                       \
  cout << endl;
#define printvec(vec)                                                          \
  for (auto xt : vec)                                                          \
    cout << xt << " ";                                                         \
  cout << "\n";

#define FD(N) fixed << setprecision(N)

#define deb(x) cout << #x << " " << x << endl;

// chandan1,2
void chandan1() {
  int y = 1;
  return;
}
void chandan2() {
  loop(i, 10) { lli x = 1; }
  return (chandan1());
}

int main() {
  fastio lli t = 1;
  // cin>>t;
  chandan2();
  while (t--) {
    lli k;
    cin >> k;
    if (k % 2 == 0 or k % 5 == 0)
      print(-1);
    else {
      lli ans = 0;
      lli cnt = 0;
      while (true) {
        ans = ans * 10 + 7;
        ans %= k;
        cnt++;
        if (ans == 0)
          break;
      }
      print(cnt);
    }
  }
  return 0;
}