Submission #745193

#	Time	Username	Problem	Language	Result	Execution time	Memory
745193		MrBrionix	Candies (JOI18_candies)	C++17	8 / 100	2259 ms	24608 KiB

candies

#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;

using i32 = std::int32_t;
using i64 = std::int64_t;
using u32 = std::uint32_t;
using u64 = std::uint64_t;
using isize = std::ptrdiff_t;
using usize = std::size_t;

const int MAXN = 200'005;
const long long INF = 1'000'000'000'000'015;

template <class Select>
std::vector<usize> smawk(const usize row_size, const usize col_size,
  const Select &select) {
  using vec_zu = std::vector<usize>;
  
  const std::function<vec_zu(const vec_zu &, const vec_zu &)> solve =
  [&](const vec_zu &row, const vec_zu &col) -> vec_zu {
    const usize n = row.size();
    if (n == 0)
      return {};
    vec_zu c2;
    for (const usize i : col) {
      while (!c2.empty() && select(row[c2.size() - 1], c2.back(), i))
        c2.pop_back();
      if (c2.size() < n)
        c2.push_back(i);
    }
    vec_zu r2;
    for (usize i = 1; i < n; i += 2)
      r2.push_back(row[i]);
    const vec_zu a2 = solve(r2, c2);
    vec_zu ans(n);
    for (usize i = 0; i != a2.size(); i += 1)
      ans[i * 2 + 1] = a2[i];
    usize j = 0;
    for (usize i = 0; i < n; i += 2) {
      ans[i] = c2[j];
      const usize end = i + 1 == n ? c2.back() : ans[i + 1];
      while (c2[j] != end) {
        j += 1;
        if (select(row[i], ans[i], c2[j]))
          ans[i] = c2[j];
      }
    }
    return ans;
  };
  vec_zu row(row_size);
  std::iota(row.begin(), row.end(), 0);
  vec_zu col(col_size);
  std::iota(col.begin(), col.end(), 0);
  return solve(row, col);
}

template<class T>
vector<T> MaxConvolutionWithConvexShape(vector<T> anyShape, 
  const vector<T> &convexShape) {
  
  if((int) convexShape.size() <= 1) return anyShape;
  if(anyShape.empty()) anyShape.push_back(0);
  int n = (int)anyShape.size(), m = (int)convexShape.size();
  auto function = [&](int i, int j) {
    //if(i-j<0 || i-j>=m) return -LLONG_MAX/3ll;
    //if(j<0 || j>=n) return -LLONG_MAX/3ll;
    return anyShape[j] + convexShape[i-j];
  };
  auto comparator = [&](int i, int j, int k) {
    if(i < k) return false;
    if(i - j >= m) return true;
    return function(i, j) <= function(i, k);
  };
  const vector<usize> best = smawk(n + m - 1 , n, comparator);
  vector<T> ans(n + m - 1);
  for(int i = 0; i < n + m - 1; i++)
    ans[i] = function(i, best[i]);
  return ans;
} //$\mathit{ans}_i=\max_{j+k=i}(A_j+B_k)$


int n,r;
long long a[MAXN];
struct dp{
  vector<long long> mat[2][2];
  
  dp(){}
  
  dp(int n){
    mat[0][0]=vector<long long>(n+1,LLONG_MIN);
    mat[0][1]=vector<long long>(n+1,LLONG_MIN);
    mat[1][0]=vector<long long>(n+1,LLONG_MIN);
    mat[1][1]=vector<long long>(n+1,LLONG_MIN);
  }
  
  dp(vector<long long> a,vector<long long>b,vector<long long>c,vector<long long>d){
    mat[0][0]=a;
    mat[0][1]=b;
    mat[1][0]=c;
    mat[1][1]=d;
  }
};

dp f(int l,int r){
  if(l+1==r){
    return dp({0,-INF},{-INF,-INF},{-INF,-INF},{-INF,a[l]});
  }
  
  if(l+2==r){
    return dp({0,-INF,-2ll*INF-1ll},{-INF,a[l+1],-INF},{-INF,a[l],-INF},{-3ll*INF-3ll,-2*INF-1ll,-INF});
  }
  
  dp res(r-l),le,ri;
  
  if((r-l)%2 == 1){
    le = f(l,(l+r)/2+1);
    ri = f((l+r)/2,r);
  }else{
    le = f(l,(l+r)/2);
    ri = f((l+r)/2-1,r);
  }
  
  for(int i=0;i<2;i++){
    for(int j=0;j<2;j++){
      for(int k=0;k<2;k++){
        auto tmp = MaxConvolutionWithConvexShape(le.mat[i][k],ri.mat[k][j]);
        for(int ll=0;ll<=r-l;ll++){
          res.mat[i][j][ll] = max(res.mat[i][j][ll],tmp[ll+k]-k*a[(r-l)%2 == 1 ? (l+r)/2 : (l+r)/2-1]);
        }
      }
    }
  }
  
  return res;
}

void solve(){
  cin>>n;
  //cin>>r;
  //n = 90'000;
  for(int i=0;i<n;i++){
    cin>>a[i];
    //a[i]=10;
  }
  
  auto tmp = f(0,n);
  
  for(int i=1;i<=(n+1)/2;i++)
    cout<<max({tmp.mat[0][0][i],tmp.mat[0][1][i],tmp.mat[1][0][i],tmp.mat[1][1][i]})<<"\n";
}

signed main(){
  //ios::sync_with_stdio(false);
  //cin.tie(0);
  
  int t=1;
  //cin>>t;
  for(int i=1;i<=t;i++)solve();
  
  return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 0 / 92