Submission #1073198

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073198		vjudge1	Tricks of the Trade (CEOI23_trade)	C++17	10 / 100	322 ms	383572 KiB

trade

#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;

using ll = long long;
using ld = long double;

//#define int ll
#define sz(x) ((int)(x).size())

using pii = pair<int,int>;
using tii = tuple<int,int,int>;

const int nmax = 2e5 + 5;

int K;

template<typename T>
struct Deq {
   vector<T> v;
   void push_front(T x) { v.emplace_back(x); }
   T& operator[](const int& x) { return rbegin(v)[x]; }
   void resize(int k) {
      if(k >= sz(v)) return;
      v.erase(begin(v), begin(v) + sz(v) - k);
      return;
   }
   int size() { return sz(v); }
}; // trebuie facut persistent

struct Tree {
   vector<int> g[nmax];
   int p[nmax];
   void add_edge(int a, int b) {
      g[a].emplace_back(b);
      p[b] = a;
   }
   
   struct mdeq : Deq<ll> {
      ll lazy = 0;
   };
   
   mdeq dp[nmax];
   int calculated[nmax];
   Tree() {
      memset(calculated, 0, sizeof(calculated));
   }
   template<class CB, class CB2> void calcdp(CB&& cost, CB2 atr, int node) {
      if(calculated[node]) return;
      calculated[node] = 1;
      
      
      for(auto x : g[node]) {
         cerr << node << " <-- " << x << '\n';
         calcdp(cost, atr, x);
         dp[x].resize(K);
         bool swapped = 0;
         
         auto T = dp[x];
         
         if(sz(T) > sz(dp[node]))
            swap(T, dp[node]);
            
         for(int i = 0; i < sz(T); i++)
            dp[node][i] = max(T[i] + T.lazy - dp[node].lazy, dp[node][i]);
      }
      dp[node].push_front(cost(node) - dp[node].lazy);
      dp[node].lazy += atr(node);
      //cerr << node << ' ' << cost(node) << ' ' << atr(node) << ": ";
      //for(int i = 0; i < sz(dp[node]); i++) cerr << dp[node][i] + dp[node].lazy << ' ';
      //cerr << '\n';
      return;
   }
};

ll spart[nmax];

signed main() {
   cin.tie(0) -> sync_with_stdio(0);
   int n;
   cin >> n >> K;
   
   for(int i = 1, x; i <= n; i++) {
      cin >> spart[i];
      spart[i] += spart[i - 1];
   }
   
   vector<int> v(n + 1);
   for(int i = 1; i <= n; i++) cin >> v[i];
   Tree toleft, toright;
   
   vector<int> st;
   
   for(int i = 1; i <= n; i++) {
      while(sz(st) && v[st.back()] <= v[i]) st.pop_back();
      if(sz(st) == 0) toleft.add_edge(0, i);
      else toleft.add_edge(st.back(), i), toright.add_edge(i, st.back());
      st.emplace_back(i);
   }
   st.clear();
   
   for(int i = n; i > 0; i--) {
      while(sz(st) && v[st.back()] < v[i]) st.pop_back();
      if(sz(st) == 0) toright.add_edge(0, i);
      else toright.add_edge(st.back(), i), toleft.add_edge(i, st.back());
      st.emplace_back(i);
   }
   st.clear();
   
   toleft.calcdp([&](int x) { return x == 0? 0 : -spart[x]; }, [&](int x) { return v[x]; }, 0);
   toright.calcdp([&](int x) { return x == 0? 0 : spart[x - 1]; }, [&](int x) { return v[x]; }, 0);

   ll best_cost = -1e18;

   for(int P = 1; P <= n; P++) {
      auto& X = toleft.dp[P];
      auto& Y = toright.dp[P];
      //cerr << sz(X) << ' ' << sz(Y) << '\n';
      if(sz(X) > sz(Y)) swap(X, Y);
      
      for(int i = 0; i < min(K, sz(X)); i++) {
         int j = K - i - 1;
         if(j >= sz(Y)) continue;
         
         best_cost = max(best_cost, X[i] + Y[j] + X.lazy + Y.lazy - v[P]);
      } 
   }
   
   cout << best_cost << '\n';
}


/**
      Töte es durch genaue Untersuchung\Töte es kann es nur noch schlimmer machen\Es lässt es irgendwie atmen
--
*/ 

Compilation message (stderr)

trade.cpp: In function 'int main()':
trade.cpp:83:19: warning: unused variable 'x' [-Wunused-variable]
   83 |    for(int i = 1, x; i <= n; i++) {
      |                   ^
trade.cpp: In instantiation of 'void Tree::calcdp(CB&&, CB2, int) [with CB = main()::<lambda(int)>; CB2 = main()::<lambda(int)>]':
trade.cpp:110:94:   required from here
trade.cpp:57:15: warning: unused variable 'swapped' [-Wunused-variable]
   57 |          bool swapped = 0;
      |               ^~~~~~~
trade.cpp: In instantiation of 'void Tree::calcdp(CB&&, CB2, int) [with CB = main()::<lambda(int)>; CB2 = main()::<lambda(int)>]':
trade.cpp:111:98:   required from here
trade.cpp:57:15: warning: unused variable 'swapped' [-Wunused-variable]
trade.cpp: In instantiation of 'void Tree::calcdp(CB&&, CB2, int) [with CB = main()::<lambda(int)>&; CB2 = main()::<lambda(int)>]':
trade.cpp:55:16:   required from 'void Tree::calcdp(CB&&, CB2, int) [with CB = main()::<lambda(int)>; CB2 = main()::<lambda(int)>]'
trade.cpp:110:94:   required from here
trade.cpp:57:15: warning: unused variable 'swapped' [-Wunused-variable]
trade.cpp: In instantiation of 'void Tree::calcdp(CB&&, CB2, int) [with CB = main()::<lambda(int)>&; CB2 = main()::<lambda(int)>]':
trade.cpp:55:16:   required from 'void Tree::calcdp(CB&&, CB2, int) [with CB = main()::<lambda(int)>; CB2 = main()::<lambda(int)>]'
trade.cpp:111:98:   required from here
trade.cpp:57:15: warning: unused variable 'swapped' [-Wunused-variable]

• Subtask 0: 0 / 0
• Subtask 1: 5 / 10
• Subtask 2: 5 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 25
• Subtask 5: 0 / 45