Problem p03660 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <cassert>
#include <cmath>
#include <deque>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unistd.h>
#include <unordered_map>
#include <vector>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<vvd> vvvd;
typedef pair<int, int> P;
typedef pair<ll, ll> PL;
typedef vector<P> vp;
typedef vector<PL> vpl;
typedef vector<vector<P>> vvp;
typedef vector<vector<PL>> vvpl;
const int INF = 1001001001;
const ll LINF = 1e16;
const double pi = 3.1415926535897932;
const string endstr = "\n";
#define FOR(i, a, b) for (ll i = (a); i < b; i++)
#define RFOR(i, a, b) for (ll i = (a); i > b; i--)
#define REP(i, n) for (ll i = 0; i < n; i++)
#define RREP(i, n) for (ll i = n - 1; i > -1; i--)
#define FORMAP(it, m) for (auto it = m.begin(); it != m.end(); it++)
#define ff first
#define ss second
#define pb push_back
#define epb emplace_back

template <typename T> T gcd(T a, T b) { return (a == 0) ? b : gcd(b % a, a); }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

bool p_comp_fs(const PL p1, const PL p2) { return p1.first < p2.first; };
bool p_comp_fg(const PL p1, const PL p2) { return p1.first > p2.first; };
bool p_comp_ss(const PL p1, const PL p2) { return p1.second < p2.second; };
bool p_comp_sg(const PL p1, const PL p2) { return p1.second > p2.second; };
template <typename T> vector<T> uniquen(vector<T> vec) {
  vec.erase(unique(vec.begin(), vec.end()), vec.end());
  return vec;
}

struct edge {
  ll to, cost;
};
const ll mx = 1e5 + 100;
vector<edge> ed[10];
ll N;

vl dijkstra(ll st) {
  vl dist(N, LINF);
  dist[st] = 0;
  priority_queue<PL, vector<PL>, greater<PL>> q;
  q.push({0, st});
  while (!q.empty()) {
    auto tmp = q.top();
    q.pop();
    ll now = tmp.ss, dis = tmp.ff;
    if (dist[now] < dis)
      continue;
    for (auto &e : ed[now]) {
      if (dist[e.to] > dis + e.cost) {
        dist[e.to] = dis + e.cost;
        q.emplace(dist[e.to], e.to);
      }
    }
  }
  return dist;
}

int main() {
  cin >> N;

  REP(i, N - 1) {
    ll a, b;
    cin >> a >> b;
    a--;
    b--;
    ed[a].pb({b, 1});
    ed[b].pb({a, 1});
  }
  auto df = dijkstra(0);
  auto ds = dijkstra(N - 1);

  ll cnt = 0;
  REP(i, N) {
    if (df[i] <= ds[i])
      cnt++;
  }
  cout << (cnt >= N / 2 + 1 ? "Fennec" : "Snuke") << endl;
  return 0;
}


Fixed submission:
#include <algorithm>
#include <cassert>
#include <cmath>
#include <deque>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unistd.h>
#include <unordered_map>
#include <vector>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<vvd> vvvd;
typedef pair<int, int> P;
typedef pair<ll, ll> PL;
typedef vector<P> vp;
typedef vector<PL> vpl;
typedef vector<vector<P>> vvp;
typedef vector<vector<PL>> vvpl;
const int INF = 1001001001;
const ll LINF = 1e16;
const double pi = 3.1415926535897932;
const string endstr = "\n";
#define FOR(i, a, b) for (ll i = (a); i < b; i++)
#define RFOR(i, a, b) for (ll i = (a); i > b; i--)
#define REP(i, n) for (ll i = 0; i < n; i++)
#define RREP(i, n) for (ll i = n - 1; i > -1; i--)
#define FORMAP(it, m) for (auto it = m.begin(); it != m.end(); it++)
#define ff first
#define ss second
#define pb push_back
#define epb emplace_back

template <typename T> T gcd(T a, T b) { return (a == 0) ? b : gcd(b % a, a); }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

bool p_comp_fs(const PL p1, const PL p2) { return p1.first < p2.first; };
bool p_comp_fg(const PL p1, const PL p2) { return p1.first > p2.first; };
bool p_comp_ss(const PL p1, const PL p2) { return p1.second < p2.second; };
bool p_comp_sg(const PL p1, const PL p2) { return p1.second > p2.second; };
template <typename T> vector<T> uniquen(vector<T> vec) {
  vec.erase(unique(vec.begin(), vec.end()), vec.end());
  return vec;
}

struct edge {
  ll to, cost;
};
const ll mx = 1e5 + 100;
vector<edge> ed[mx];
ll N;

vl dijkstra(ll st) {
  vl dist(N, LINF);
  dist[st] = 0;
  priority_queue<PL, vector<PL>, greater<PL>> q;
  q.push({0, st});
  while (!q.empty()) {
    auto tmp = q.top();
    q.pop();
    ll now = tmp.ss, dis = tmp.ff;
    if (dist[now] < dis)
      continue;
    for (auto &e : ed[now]) {
      if (dist[e.to] > dis + e.cost) {
        dist[e.to] = dis + e.cost;
        q.emplace(dist[e.to], e.to);
      }
    }
  }
  return dist;
}

int main() {
  cin >> N;

  REP(i, N - 1) {
    ll a, b;
    cin >> a >> b;
    a--;
    b--;
    ed[a].pb({b, 1});
    ed[b].pb({a, 1});
  }
  auto df = dijkstra(0);
  auto ds = dijkstra(N - 1);

  ll cnt = 0;
  REP(i, N) {
    if (df[i] <= ds[i])
      cnt++;
  }
  cout << (cnt >= N / 2 + 1 ? "Fennec" : "Snuke") << endl;
  return 0;
}