Problem p03966 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
using namespace std;

typedef long long signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for (int i = (l); i < (r); i++)
#define incII(i, l, r) for (int i = (l); i <= (r); i++)
#define decID(i, l, r) for (int i = (r)-1; i >= (l); i--)
#define decII(i, l, r) for (int i = (r); i >= (l); i--)
#define inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) < (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define UB upper_bound
#define LB lower_bound
#define PQ priority_queue

#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
#define FOR(it, v) for (auto it = v.begin(); it != v.end(); ++it)
#define RFOR(it, v) for (auto it = v.rbegin(); it != v.rend(); ++it)

template <typename T> bool setmin(T &a, T b) {
  if (b < a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmax(T &a, T b) {
  if (b > a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmineq(T &a, T b) {
  if (b <= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmaxeq(T &a, T b) {
  if (b >= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

LL n, t[1000], a[1000];

int main() {
  cin >> n;
  inc(i, n) { cin >> t[i] >> a[i]; }

  LL min_t = t[0], min_a = a[0];
  inc(i, n) {
    LL k = 1;
    while (!(min_t <= t[i] * k && min_a <= a[i] * k)) {
      k++;
    }
    min_t = t[i] * k;
    min_a = a[i] * k;
  }

  cout << min_t + min_a << endl;

  return 0;
}


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

typedef long long signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for (int i = (l); i < (r); i++)
#define incII(i, l, r) for (int i = (l); i <= (r); i++)
#define decID(i, l, r) for (int i = (r)-1; i >= (l); i--)
#define decII(i, l, r) for (int i = (r); i >= (l); i--)
#define inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) < (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define UB upper_bound
#define LB lower_bound
#define PQ priority_queue

#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
#define FOR(it, v) for (auto it = v.begin(); it != v.end(); ++it)
#define RFOR(it, v) for (auto it = v.rbegin(); it != v.rend(); ++it)

template <typename T> bool setmin(T &a, T b) {
  if (b < a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmax(T &a, T b) {
  if (b > a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmineq(T &a, T b) {
  if (b <= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmaxeq(T &a, T b) {
  if (b >= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

LL n, t[1000], a[1000];

int main() {
  cin >> n;
  inc(i, n) { cin >> t[i] >> a[i]; }

  LL min_t = t[0], min_a = a[0];
  inc(i, n) {
    LL k = max((min_t + t[i] - 1) / t[i], (min_a + a[i] - 1) / a[i]);

    min_t = t[i] * k;
    min_a = a[i] * k;
  }

  cout << min_t + min_a << endl;

  return 0;
}