4 files changed, 151 insertions, 0 deletions
diff --git a/contests/Round#857/B/main b/contests/Round#857/B/main
new file mode 100755
index 0000000..fa8f5c5
--- /dev/null
+++ b/contests/Round#857/B/main
diff --git a/contests/Round#857/B/main.cpp b/contests/Round#857/B/main.cpp
new file mode 100755
index 0000000..324c05c
--- /dev/null
+++ b/contests/Round#857/B/main.cpp
@@ -0,0 +1,132 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pi = pair<int, int>;
+using vpi = vector<pi>;
+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
+
+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};
+
+//pretty printing
+template<typename K, typename V>
+void printm(const map<K, V> &mp) {
+  cerr << "{" << endl;
+  for (auto p : mp) {
+    cerr << "  { " << p.first << " : " << p.second << " }\n";
+  }
+  cerr << "}" << endl;
+}
+template<typename T>
+void printv(const vector<T> &v) {
+  cerr << "[";
+  for (int i = 0; i < v.size(); i++) {
+    if (i == v.size() - 1) {
+      cerr << v[i];
+    } else {
+      cerr << v[i] << ", ";
+    }
+  }
+  cerr << "]\n";
+}
+
+template<typename T>
+void printvv(const vector<vector<T>> &v) {
+  cerr << "[\n";
+  for (auto &vec : v) {
+    cout << "  ";
+    printv(vec);
+  }
+  cerr << "]\n";
+}
+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
+ */
+
+vi helper(vi &v) {
+  vi ret;
+  v.pb(2);
+  int x = 0;
+  for (int i = 0; i < v.size(); i++) {
+    if (v[i] == 1) {
+      x++;
+    } else {
+      if (x != 0)  {
+        ret.pb(x);
+      }
+      x = 0;
+    }
+  }
+  return ret;
+}
+
+// 10 2 3 4
+// max(1 + 10 / 2 + 2, 10)
+// max(1 + 12 / 2 + 3, 10)
+// max(1 + 15 / 2 + 4, 10)
+// max(1 + 15 / 2 + 4, 11)
+
+void solve() {
+  int n;
+  uint32_t x;
+  cin >> n;
+  vi v(n);
+  for (auto &x : v) cin >> x;
+  vi tmp = v;
+  vi ret = helper(tmp);
+  if(ret.size() == 0) {
+    cout << 0 << '\n';
+    return;
+  }
+  int pfx = ret[0];
+  int ans = ret[0];
+  for (int i = 1; i < ret.size(); i++) {
+    if (ret[i] == 0) continue;
+    ans = max(1 + pfx / 2 + ret[i], ans);
+    pfx += ret[i];
+  }
+  cout << ans << '\n';
+
+}
+
+int main () {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while(tt--) {
+    solve();
+  }
+}
+
+
diff --git a/contests/Round#857/B/main_input0.txt b/contests/Round#857/B/main_input0.txt
new file mode 100644
index 0000000..d60568c
--- /dev/null
+++ b/contests/Round#857/B/main_input0.txt
@@ -0,0 +1,13 @@
+6
+3
+1 1 1
+3
+2 2 2
+5
+1 1 1 2 1
+10
+1 2 1 2 1 2 1 2 1 2
+20
+1 2 1 1 1 1 1 2 1 2 1 2 2 1 1 1 1 1 1 1
+20
+2 1 1 2 1 1 2 1 2 2 1 1 1 2 2 1 1 1 1 2
diff --git a/contests/Round#857/B/main_output0.txt b/contests/Round#857/B/main_output0.txt
new file mode 100644
index 0000000..ea5c498
--- /dev/null
+++ b/contests/Round#857/B/main_output0.txt
@@ -0,0 +1,6 @@
+3
+0
+3
+4
+12
+9