cleanup

codeforces/1054/d.cc

@@ -0,0 +1,93 @@
+#include <bits/stdc++.h> // {{{
+
+#include <version>
+#ifdef __cpp_lib_ranges_enumerate
+#include <ranges>
+namespace rv = std::views;
+namespace rs = std::ranges;
+#endif
+
+// https://codeforces.com/blog/entry/96344
+
+#pragma GCC optimize("O2,unroll-loops")
+#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
+
+using namespace std;
+
+using i16 = int16_t;
+using u16 = uint16_t;
+using i32 = int32_t;
+using u32 = uint32_t;
+using i64 = int64_t;
+using u64 = uint64_t;
+using f64 = double;
+using f128 = long double;
+
+#if __cplusplus >= 202002L
+template <typename T> constexpr T MIN = std::numeric_limits<T>::min();
+
+template <typename T> constexpr T MAX = std::numeric_limits<T>::max();
+#endif
+
+#ifdef LOCAL
+#define db(...) std::print(__VA_ARGS__)
+#define dbln(...) std::println(__VA_ARGS__)
+#else
+#define db(...)
+#define dbln(...)
+#endif
+//  }}}
+
+void solve() {
+  u32 n;
+  string s;
+  cin >> n >> s;
+
+  u64 ans = MAX<u64>;
+
+  auto f = [&](string &t) {
+    vector<u64> pos;
+    for (u64 i = 0; i < n; i++)
+      if (t[i] == 'a')
+        pos.push_back(i);
+    u64 m = pos.size();
+
+    vector<u64> pref(m + 1), suff(m + 1);
+    for (u64 i = 0; i < m; i++)
+      pref[i + 1] = pref[i] + pos[i] - i;
+    for (u64 i = m; i--;)
+      suff[i] = suff[i + 1] + (n - (m - i)) - pos[i];
+
+    for (u64 i = 0; i <= m; i++)
+      ans = min<u64>(ans, pref[i] + suff[i]);
+  };
+
+  f(s);
+  transform(s.begin(), s.end(), s.begin(),
+            [](char c) { return c ^ 'a' ^ 'b'; });
+  f(s);
+
+  cout << ans << '\n';
+}
+
+int main() { // {{{
+  std::cin.exceptions(std::cin.failbit);
+
+#ifdef LOCAL
+  std::cerr.rdbuf(std::cout.rdbuf());
+  std::cout.setf(std::ios::unitbuf);
+  std::cerr.setf(std::ios::unitbuf);
+#else
+  std::cin.tie(nullptr)->sync_with_stdio(false);
+#endif
+
+  u32 tc = 1;
+  std::cin >> tc;
+
+  for (u32 t = 0; t < tc; ++t) {
+    solve();
+  }
+
+  return 0;
+}
+// }}}

codeforces/1054/io/2149a.cpin

@@ -0,0 +1,11 @@
+5
+4
+abab
+6
+bababa
+7
+abababa
+2
+ab
+1
+b

codeforces/1054/io/d.1.cpin

@@ -0,0 +1,11 @@
+5
+4
+abab
+6
+bababa
+7
+abababa
+2
+ab
+1
+b