#include <bits/stdc++.h>
 
using namespace std;
 
void solve() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  cout << s.back() << '\n';
}
 
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}

• Didnt solve
• Good problem
• Average problem
• Bad problem
• tROlll pRoBlEm

#include <bits/stdc++.h>
 
using namespace std;
const int N = 100;
 
void solve() {
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  vector<int> b(n, 1);
  vector<vector<int>> inds(N + 1);
  for (int i = 0; i < n; i++) {
    inds[a[i]].push_back(i);
  }
  int k = 2;
  for (int x = 1; x <= N; x++) {
    if ((int) inds[x].size() >= 2) {
      b[inds[x][0]] = k;
      k++;
      if (k > 3) {
        break;
      }
    }
  }
  if (k <= 3) {
    cout << "-1\n";
  } else {
    for (int i = 0; i < n; i++) {
      cout << b[i] << ' ';
    }
    cout << '\n';
  }
}
 
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}

• Didnt solve
• Good problem
• Average problem
• Bad problem

#include <bits/stdc++.h>
 
using namespace std;
 
void solve() {
  int n, k;
  cin >> n >> k;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  k = min(k, n);
  int last = n - 1;
  for (int _ = 0; _ < k; _++) {
    if (a[last] > n) {
      cout << "No\n";
      return;
    }
    last += n - a[last];
    if (last >= n) {
      last -= n;
    }
  }
  cout << "Yes\n";
}
 
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}

• Didnt solve
• Good problem
• Average problem
• Bad problem

#include <bits/stdc++.h>
 
#define pb push_back
#define all(x) x.begin(), (x).end()
#define rall(x) x.rbegin(), (x).rend()
using namespace std;
 
void solve() {
  int n, m;
  cin >> n >> m;
  vector<int> a(n), b(m), c(n + m);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (int i = 0; i < m; i++) {
    cin >> b[i];
  }
  sort(rall(b));
  merge(all(a), all(b), c.begin(), greater<int>());
  for (int i = 0; i < n + m; i++) {
    cout << c[i] << ' ';
  }
  cout << '\n';
}
 
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}

• Didnt solve
• Good problem
• Average problem
• Bad problem

#include <bits/stdc++.h>
 
#define pb push_back
#define int long long
#define all(x) x.begin(), (x).end()
using namespace std;
 
void solve() {
  int m;
  cin >> m;
  vector<int> n(m), l(m), r(m);
  vector<vector<int>> a(m);
  vector<vector<int>> c(m);
  vector<int> sumc(m);
  int suml = 0, sumr = 0, sumn = 0;
  for (int i = 0; i < m; i++) {
    cin >> n[i] >> l[i] >> r[i];
    sumn += n[i];
    suml += l[i];
    sumr += r[i];
    a[i].resize(n[i]);
    for (int j = 0; j < n[i]; j++) {
      cin >> a[i][j];
    }
    c[i].resize(n[i]);
    for (int j = 0; j < n[i]; j++) {
      cin >> c[i][j];
      sumc[i] += c[i][j];
    }
  }
  
  if (sumr - suml > sumn) {
    cout << "0\n";
    return;
  }
 
  map<int, int> sumr_a;
  map<int, vector<pair<int, int>>> indexes;
  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n[i]; j++) {
      sumr_a[a[i][j]] += r[i];
      indexes[a[i][j]].pb({i, j});
    }
  }
 
  int ans = (int) 2e18;
  for (int len = suml; len <= sumr; len++) {
    int xsize = 0, must_len = 0;
    xsize += sumr - sumr_a[len];
    for (auto &[i, pos] : indexes[len]) {
      int cnt_not_len = sumc[i] - c[i][pos];
      if (cnt_not_len < l[i]) {
        xsize += l[i];
        must_len += l[i] - cnt_not_len;
      } else {
        xsize += min(cnt_not_len, r[i]);
      }
    }
    ans = min(ans, must_len + max(0LL, len - xsize));
  }
  cout << ans << '\n';
}
 
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}

• Didnt solve
• Good problem
• Average problem
• Bad problem

#include <bits/stdc++.h>
 
#define pb push_back
#define all(x) x.begin(), (x).end()
#define rall(x) x.rbegin(), (x).rend()
using namespace std;
 
void solve() {
  int n, m;
  cin >> n >> m;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  vector<int> s(m), d(m);
  for (int i = 0; i < m; i++) {
    cin >> s[i];
  }
  for (int i = 0; i < m; i++) {
    cin >> d[i];
  }
  vector<int> cnt(n + 1);
  for (int i = 0; i < n; i++) {
    cnt[a[i]]++;
  }
 
  set<pair<int, int>> cubes;
  for (int x = 1; x <= n; x++) {
    if (cnt[x] == 0) continue;
    cubes.insert({cnt[x], x});
  }
 
  vector<vector<int>> ans(m);
 
  for (int i = 0; i < m; i++) {
    ans[i].assign(s[i], 0);
    for (int j = 0; j < s[i]; j++) {
      if (j >= d[i]) {
        if (cnt[ans[i][j - d[i]]] > 0) {
          cubes.insert({cnt[ans[i][j - d[i]]], ans[i][j - d[i]]});
        }
      }
      if (cubes.empty()) {
        cout << "-1\n";
        return;
      }
      ans[i][j] = (*cubes.rbegin()).second;
      cubes.erase(*cubes.rbegin());
      cnt[ans[i][j]]--;
    }
    for (int j = s[i]; j < s[i] + d[i]; j++) {
      if (cnt[ans[i][j - d[i]]] > 0) {
        cubes.insert({cnt[ans[i][j - d[i]]], ans[i][j - d[i]]});
      }
    }
  }
 
  for (int i = 0; i < m; i++) {
    for (int j = 0; j < s[i]; j++) {
      cout << ans[i][j] << ' ';
    }
    cout << '\n';
  }
 
}
 
 
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}

• Didnt solve
• Good problem
• Average problem
• Bad problem

#include <bits/stdc++.h>
 
typedef long long ll;
#define pb push_back
 
using namespace std;
 
const int M = 998244353;
const int N = 500500;
vector<pair<int, int>> g[N];
set<int> bridgesV[N];
bitset<N> used;
int h[N], d[N];
ll bridges = 0;
ll solo = 0;
 
int binpow(ll a, ll x) {
  ll ans = 1;
  while (x) {
    if (x % 2) {
      ans *= a;
      ans %= M;
    }
    a *= a;
    a %= M;
    x /= 2;
  }
  return (int) ans;
}
 
void dfs(int v, int p = -1) {
  if (p != -1) {
    d[v] = h[p] + 1;
    h[v] = h[p] + 1;
  }
  used[v] = true;
  for (auto &[u, w] : g[v]) {
    if (u == p) continue;
    if (!used[u]) {
      dfs(u, v);
      d[v] = min(d[v], d[u]);
      if (h[v] < d[u]) {
        bridgesV[v].insert(u);
        bridgesV[u].insert(v);
        bridges += w + 1;
        solo += w;
      }
    } else {
      d[v] = min(d[v], h[u]);
    }
  }
}
 
int calc_dp(ll n) {
  n %= (M - 1);
  if (n == 1) return 3;
  if (n == 2) return 0;
  int val = binpow(2, n);
  if (n % 2 == 1) {
    val += M - 2;
  } else {
    val += 2;
  }
  val %= M;
  return val;
}
 
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    int a, b, w;
    cin >> a >> b >> w;
    a--;
    b--;
    g[a].pb({b, w});
    g[b].pb({a, w});
  }
  if (n % 2 != m % 2) {
    cout << "0\n";
    return 0;
  }
  dfs(0);
  used.reset();
 
  ll ans = 1;
  for (int v = 0; v < n; v++) {
    if (!used[v]) {
      ll cs = 0;
      vector<int> q = {v};
      used[v] = true;
      while (!q.empty()) {
        int u = q.back();
        q.pop_back();
        for (auto &[uu, w] : g[u]) {
          if (bridgesV[u].find(uu) != bridgesV[u].end()) continue;
          cs += w + 1;
          if (!used[uu]) {
            used[uu] = true;
            q.pb(uu);
          }
        }
      }
      cs /= 2;
      cs = max(cs, 1LL);
      ans *= calc_dp(cs);
      ans %= M;
    }
  }
  ans *= binpow(3, solo);
  ans %= M;
  int w = (2 * binpow(3, M - 2)) % M;
  ans *= binpow(w, bridges);
  ans %= M;
  int cycles = (m + 1) - n;
  ans *= binpow(2, cycles);
  ans %= M;
  cout << ans << '\n';
}

• Didnt solve
• Good problem
• Average problem
• Bad problem