Problem p03506 (C++)

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

#include <algorithm>
#include <iostream>

#include <array>
#include <bitset>
#include <complex>
#include <cstring>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <valarray>
#include <vector>

#include <cassert>
#include <chrono>
#include <cmath>
#include <functional>
#include <iomanip>
#include <numeric>
#include <random>

using namespace std;
#define int long long

typedef long long ll;
typedef unsigned long long ull;
// typedef unsigned __int128 HASH;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pullull;
typedef pair<ll, int> plli;
typedef pair<double, int> pdbi;
typedef pair<int, pii> pipii;
typedef pair<ll, pll> plpll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<pii> vpii;
typedef vector<vector<int>> mat;

#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define rrep(i, n) for (int i = (n); i > 0; i--)
#define rrep2(i, a, b) for (int i = (a); i > b; i--)
#define pb push_back
#define fi first
#define se second
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()

const ll hmod1 = 999999937;
const ll hmod2 = 1000000000 + 9;
const int INF = 1 << 30;
const ll INFLL = 1LL << 62;
const double EPS = 1e-12;
const ll mod = 1000000000 + 7;
const int dx4[4] = {1, 0, -1, 0};
const int dy4[4] = {0, 1, 0, -1};
const int dx8[8] = {1, 1, 1, 0, 0, -1, -1, -1};
const int dy8[8] = {0, 1, -1, 1, -1, 0, 1, -1};
const double pi = 3.141592653589793;

#define addm(X, Y) (X) = ((X) + ((Y) % mod) + mod) % mod
#define inside(y, x, h, w)                                                     \
  (0 <= (y) && (y) < (h) && 0 <= (x) && (x) < (w)) ? true : false

int n, q;

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n >> q;
  rep(i, q) {
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    while (u != v) {
      if (u > v) {
        u = (u - 1) / n;
        continue;
      }
      if (v > u) {
        v = (v - 1) / n;
        continue;
      }
    }
    cout << u + 1 << endl;
  }
}


Fixed submission:
// #include <bits/stdc++.h>

#include <algorithm>
#include <iostream>

#include <array>
#include <bitset>
#include <complex>
#include <cstring>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <valarray>
#include <vector>

#include <cassert>
#include <chrono>
#include <cmath>
#include <functional>
#include <iomanip>
#include <numeric>
#include <random>

using namespace std;
#define int long long

typedef long long ll;
typedef unsigned long long ull;
// typedef unsigned __int128 HASH;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pullull;
typedef pair<ll, int> plli;
typedef pair<double, int> pdbi;
typedef pair<int, pii> pipii;
typedef pair<ll, pll> plpll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<pii> vpii;
typedef vector<vector<int>> mat;

#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define rrep(i, n) for (int i = (n); i > 0; i--)
#define rrep2(i, a, b) for (int i = (a); i > b; i--)
#define pb push_back
#define fi first
#define se second
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()

const ll hmod1 = 999999937;
const ll hmod2 = 1000000000 + 9;
const int INF = 1 << 30;
const ll INFLL = 1LL << 62;
const double EPS = 1e-12;
const ll mod = 1000000000 + 7;
const int dx4[4] = {1, 0, -1, 0};
const int dy4[4] = {0, 1, 0, -1};
const int dx8[8] = {1, 1, 1, 0, 0, -1, -1, -1};
const int dy8[8] = {0, 1, -1, 1, -1, 0, 1, -1};
const double pi = 3.141592653589793;

#define addm(X, Y) (X) = ((X) + ((Y) % mod) + mod) % mod
#define inside(y, x, h, w)                                                     \
  (0 <= (y) && (y) < (h) && 0 <= (x) && (x) < (w)) ? true : false

int n, q;

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n >> q;
  rep(i, q) {
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    if (n == 1) {
      cout << min(u + 1, v + 1) << endl;
      continue;
    }
    while (u != v) {
      if (u > v) {
        u = (u - 1) / n;
        continue;
      }
      if (v > u) {
        v = (v - 1) / n;
        continue;
      }
    }
    cout << u + 1 << endl;
  }
}