codeforces: 1003

codeforces/996/d.cc

@@ -0,0 +1,103 @@
+#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;
+
+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());
+}
+
+template <typename... Args>
+void pr(std::format_string<Args...> fmt, Args&&... args) {
+  std::print(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+void pr(std::format_string<Args...> fmt) {
+  std::print(fmt);
+}
+
+template <typename... Args>
+void prln(std::format_string<Args...> fmt, Args&&... args) {
+  std::println(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+void prln(std::format_string<Args...> fmt) {
+  std::println(fmt);
+}
+
+using ll = long long;
+using ld = long double;
+template <typename T>
+using vec = std::vector<T>;
+
+#define ff first
+#define ss second
+#define eb emplace_back
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+
+#define FORI(a, b, c) for (int a = (b); a < (c); ++a)
+#define ROFI(a, b, c) for (int a = (b); a > (c); --a)
+#define FORLL(a, b, c) for (ll a = (b); a < (c); ++a)
+#define ROFLL(a, b, c) for (ll a = (b); a > (c); --a)  // }}}
+
+void solve() {
+  int n;
+  cin >> n;
+  vec<ll> a(n);
+  vec<ll> prefix(n + 1, 0);
+  FORI(i, 0, n) {
+    cin >> a[i];
+    prefix[i + 1] = prefix[i] + a[i];
+  }
+  string s;
+  cin >> s;
+
+  int l = 0, r = n - 1;
+  ll ans = 0;
+
+  while (l < r) {
+    if (s[l] == 'L' && s[r] == 'R') {
+      ans += prefix[r + 1] - prefix[l];
+      ++l;
+      --r;
+    } else if (s[r] == 'L') {
+      --r;
+    } else {
+      ++l;
+    }
+  }
+  prln("{}", ans);
+}
+
+int main() {  // {{{
+  cin.tie(nullptr)->sync_with_stdio(false);
+
+  int t = 1;
+  cin >> t;
+
+  while (t--) {
+    solve();
+  }
+
+  return 0;
+}  //}}}