1 files changed, 79 insertions, 0 deletions
diff --git a/contests/Round#835/E/main.cpp b/contests/Round#835/E/main.cpp
new file mode 100644
index 0000000..68691f8
--- /dev/null
+++ b/contests/Round#835/E/main.cpp
@@ -0,0 +1,79 @@
+#include <bits/stdc++.h>
+#include <tuple>
+
+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 push_back pb
+#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};
+
+auto helper(vi &v) {
+  ll ans = 0, zc = 0;
+  for (int i = v.size() - 1; i >= 0; i--) {
+    (v[i] == 0 ? zc++ : ans += zc);
+  }
+  return ans;
+}
+
+void solve() {
+  int n;
+  cin >> n;
+  vi v(n), v1(n), v2(n);
+  for (int i = 0; i < n; i++) {
+    cin >> v[i];
+  }
+  v1 = v;
+  v2 = v;
+  for (auto &x : v1) {
+    if (x == 0) {
+      x = 1;
+      break;
+    }
+  }
+  for (int i = n - 1; i >= 0; i--) {
+    if (v2[i] == 1) {
+      v2[i] = 0;
+      break;
+    }
+  }
+  ll og = helper(v);
+  ll l = helper(v1);
+  ll r = helper(v2);
+  cout << max(og, max(r, l)) << '\n';
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
+
+/* 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
+ */
+