feat(codeforces/970): a-f

codeforces/970/d.cc

@@ -0,0 +1,163 @@
+#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 u32 = uint32_t;
+using i64 = int64_t;
+using u64 = uint64_t;
+using d64 = double;
+using d128 = long double;
+template <typename T>
+using vec = std::vector<T>;
+template <typename T, size_t N>
+using arr = std::array<T, N>;
+template <typename T1, typename T2>
+using pai = std::pair<T1, T2>;
+
+template <typename T>
+constexpr T MIN = std::numeric_limits<T>::min();
+
+template <typename T>
+constexpr T MAX = std::numeric_limits<T>::max();
+
+template <typename T>
+[[nodiscard]] static T sc(auto&& x) {
+  return static_cast<T>(x);
+}
+
+template <typename T>
+[[nodiscard]] static T sz(auto&& x) {
+  return static_cast<T>(x.size());
+}
+
+static void NO() {
+  std::cout << "NO\n";
+}
+
+static void YES() {
+  std::cout << "YES\n";
+}
+
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+
+#ifdef LOCAL
+#define db(...) std::print(__VA_ARGS__)
+#define dbln(...) std::println(__VA_ARGS__)
+#else
+#define db(...)
+#define dbln(...)
+#endif
+//  }}}
+
+bitset<2 * 100000 + 1> black;
+
+void solve() {
+  black.reset();
+
+  u32 n;
+  cin >> n;
+  vec<u32> a(n);
+  for (auto& e : a) {
+    cin >> e;
+    --e;
+  }
+
+  char c;
+  for (u32 i = 0; i < n; ++i) {
+    cin >> c;
+    if (c == '1')
+      black[i] = true;
+  }
+
+  vec<int> cycle_id(n, -1);
+  vec<int> cycle_pos(n, -1);
+  vec<bool> visited(n, false);
+  vec<int> black_count(n, 0);
+
+  for (u32 start = 0; start < n; ++start) {
+    if (visited[start])
+      continue;
+
+    u32 slow = start;
+    u32 fast = start;
+
+    do {
+      slow = a[slow];
+      fast = a[a[fast]];
+    } while (slow != fast);
+
+    u32 cycle_start = slow;
+    int cycle_length = 1;
+    slow = a[slow];
+
+    while (slow != cycle_start) {
+      cycle_length++;
+      slow = a[slow];
+    }
+
+    slow = cycle_start;
+    int cycle_black = 0;
+    for (int i = 0; i < cycle_length; ++i) {
+      cycle_id[slow] = start;
+      cycle_pos[slow] = i;
+      visited[slow] = true;
+
+      if (black[slow])
+        cycle_black++;
+
+      slow = a[slow];
+    }
+
+    black_count[start] = cycle_black;
+  }
+
+  vec<int> answer(n, 0);
+
+  for (u32 i = 0; i < n; ++i) {
+    if (cycle_id[i] != -1) {
+      answer[i] = black_count[cycle_id[i]];
+    } else {
+      vec<u32> path;
+      u32 curr = i;
+
+      while (cycle_id[curr] == -1) {
+        path.push_back(curr);
+        curr = a[curr];
+      }
+
+      for (u32 node : path) {
+        if (black[node])
+          answer[i]++;
+      }
+
+      answer[i] += black_count[cycle_id[curr]];
+    }
+  }
+
+  for (u32 i = 0; i < n; ++i) {
+    cout << answer[i] << ' ';
+  }
+  cout << '\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;
+}
+// }}}