2 files changed, 160 insertions, 0 deletions
diff --git a/contests/Round859(Div4)/E/main b/contests/Round859(Div4)/E/main
new file mode 100755
index 0000000..31ed974
--- /dev/null
+++ b/contests/Round859(Div4)/E/main
diff --git a/contests/Round859(Div4)/E/main.cpp b/contests/Round859(Div4)/E/main.cpp
new file mode 100755
index 0000000..e15145d
--- /dev/null
+++ b/contests/Round859(Div4)/E/main.cpp
@@ -0,0 +1,160 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back 
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x) sort(all((x))); (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b) - 1) / (b))
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template<typename K, typename V> ostream& operator<<(ostream& os, const pair<K, V>& p);
+template<typename T> ostream& operator<<(ostream& os, const vector<T>& vec);
+template<typename K, typename V> ostream& operator<<(ostream& os, const map<K, V>& m);
+template<typename K, typename V> ostream& operator<<(ostream& os, const unordered_map<K, V>& m);
+template<typename T> ostream& operator<<(ostream& os, const set<T>& s);
+template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& s);
+
+template<typename K, typename V>
+ostream& operator<<(ostream& os, const pair<K, V>& p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template<typename T>
+ostream& operator<<(ostream& os, const vector<T>& vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0) os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+
+template<typename K, typename V>
+ostream& operator<<(ostream& os, const map<K, V>& m) {
+  os << "{";
+  for (const auto& p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template<typename K, typename V>
+ostream& operator<<(ostream& os, const unordered_map<K, V>& m) {
+  os << "{";
+  for (const auto& p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template<typename T>
+ostream& operator<<(ostream& os, const set<T>& s) {
+  int i = 0;
+  os << "{";
+  for (const auto& e : s) {
+    if (i > 0) os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template<typename T>
+ostream& operator<<(ostream& os, const unordered_set<T>& s) {
+  int i = 0;
+  os << "{";
+  for (const auto& e : s) {
+    if (i > 0) os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void print() {
+  cerr << "\n";
+}
+
+template<typename T, typename... TS>
+void print(T val, TS... vals) {
+  cerr << val << " ";
+  print(vals...);
+}
+
+
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {
+  int n;
+  cin >> n;
+  vi v(n);
+  for (auto &x : v) {
+    cin >> x;
+  }
+  vll pref(n + 1);
+  pref[0] = 0;
+  for (int i = 0; i < n; i++) {
+    pref[i + 1] = pref[i] + v[i];
+  }
+  int l = 0, r = n - 1, mid;
+  while (l < r) {
+    int q;
+    mid = (r + l) / 2;
+    cout << "? " << mid - l + 1 << " ";
+    for (int i = l; i <= mid; i++) {
+      cout << i + 1 << " \n"[i == mid];
+    }
+    cout.flush();
+    cin >> q;
+    if (q > pref[mid + 1] - pref[l]) {
+      r = mid;
+    } else {
+      l = mid + 1;
+    }
+  }
+  cout << "! " << l + 1 << '\n';
+  cout.flush();
+}
+
+int main () {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while(tt--) {
+    solve();
+  }
+}
+
+