feat(codeforces): 799

codeforces/799/f.cc

@@ -0,0 +1,70 @@
+#include <bits/stdc++.h>  // {{{
+
+// https://codeforces.com/blog/entry/96344
+
+#pragma GCC optimize("O2,unroll-loops")
+#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
+
+using namespace std;
+
+#define prln(...) std::println(__VA_ARGS__)
+#define pr(...) std::print(__VA_ARGS__)
+
+#ifdef LOCAL
+#define dbgln(...) std::println(__VA_ARGS__)
+#define dbg(...) std::print(__VA_ARGS__)
+#else
+#define dbgln(...)
+#define dbg(...)
+#endif
+//  }}}
+
+void solve() {
+  int n;
+  cin >> n;
+  vector<int> a(n);
+  vector<int> f(10, 0);
+  for (auto& e : a)
+    cin >> e;
+
+  for (int i = 0; i < n; ++i) {
+    ++f[a[i] % 10];
+  }
+  // NOTE: missed n - 2, did just < n
+  // NOTE: also, removed f[digit] after, causing a[i] % 10 to be
+  // included in f erroneously
+  for (int i = 0; i < n - 2; ++i) {
+    int digit = a[i] % 10;
+    --f[digit];
+
+    for (int l = 0; l <= 9; ++l) {
+      for (int r = 0; r <= 9; ++r) {
+        if ((l + r + digit) % 10 == 3) {
+          // NOTE: forgot l != r condition
+          // simplify conditions
+          if ((l == r && f[l] >= 2) || (l != r && f[l] >= 1 && f[r] >= 1)) {
+            cout << "YES\n";
+            return;
+          }
+        }
+      }
+    }
+  }
+
+  cout << "NO\n";
+}
+
+int main() {  // {{{
+  cin.tie(nullptr)->sync_with_stdio(false);
+  cin.exceptions(cin.failbit);
+
+  int tc = 1;
+  cin >> tc;
+
+  for (int t = 0; t < tc; ++t) {
+    solve();
+  }
+
+  return 0;
+}
+// }}}