feat(cses); refactor structure

codeforces/835/d.cc

@@ -0,0 +1,51 @@
+#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;
+
+using i32 = int32_t;
+using u4 = uint32_t;
+using i64 = int64_t;
+using u64 = uint64_t;
+using f64 = double;
+using f128 = long double;
+//  }}}
+
+void solve() {
+  u4 n;
+  cin >> n;
+  vector<u4> a(n);
+  for (auto& e : a)
+    cin >> e;
+  u4 i = 0;
+  while (i < n - 1 && a[i] >= a[i + 1]) {
+    ++i;
+  }
+  while (i < n - 1 && a[i] <= a[i + 1]) {
+    ++i;
+  }
+
+  if (i == n - 1)
+    cout << "YES\n";
+  else
+    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;
+}
+// }}}