Submission #705602

#	Time	Username	Problem	Language	Result	Execution time	Memory
705602		epicci23	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	95 ms	129348 KiB

ho_t3

#include "bits/stdc++.h"
#pragma optimize ("Bismillahirrahmanirrahim")
using namespace std;
#define pb push_back
#define ff first
#define ss second
#define endl "\n" 
#define int long long
#define double long double
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define what_is(x) cerr << #x << " is " << x << endl;
//#define m (l+r)/2
constexpr int N=200005;
constexpr int MOD=1000000007;
constexpr int  INF2 = LLONG_MAX;
constexpr int INF=(int)1e18;
constexpr int LOG=30;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tp;
typedef priority_queue<pii,vector<pii>,greater<pii>> min_pq;
typedef priority_queue<pii> max_pq;
typedef long long ll;
//to think//
/*
 * graph approach
 * dp
 * dividing the problem to smaller statements
 * finding the real constraint
 * sqrt decomposition
 * greedy approach
 * pigeonhole principle
 * rewriting the problem/equality 
 * bitwise approaches
 * binary search if monotonic
 * divide and conquer
 * combinatorics
 * inclusion - exclusion
 * think like bfs
*/



inline int in()
{
  int x;cin >> x;
  return x;
}

inline string in2()
{
  string x;cin >> x;
  return x;
}

array<int,2> arr[205];
int dp[202][202][202][2];




void solve()
{
  int n=in(),l=in();
  
  for(int i=0;i<=n+1;i++)
    for(int j=0;j<=n+1;j++)
      for(int k=0;k<=n+1;k++)
        dp[i][j][k][0]=dp[i][j][k][1]=INF;

  for(int i=1;i<=n;i++) arr[i][0]=in();
  for(int i=1;i<=n;i++) arr[i][1]=in();
  
  arr[0][0]=0;
  arr[n+1][0]=l;

  dp[0][n+1][0][0]=dp[0][n+1][0][1]=0;
  int ans=0;
  for(int i=0;i<=n;i++)
  {
    for(int j=n+1;j>i;j--)
    {
      for(int k=0;k<=n;k++)
      {
        if(dp[i][j][k][0]!=INF)
        {
          ans=max(ans,k);
          int ol=dp[i][j][k][0]+arr[i+1][0]-arr[i][0];
          dp[i+1][j][k+(ol<=arr[i+1][1])][0]=min(dp[i+1][j][k+(ol<=arr[i+1][1])][0],ol);
          int ol2=dp[i][j][k][0]+arr[i][0]+l-arr[j-1][0];
          dp[i][j-1][k+(ol2<=arr[j-1][1])][1]=min(dp[i][j-1][k+(ol2<=arr[j-1][1])][1],ol2);
        }
        if(dp[i][j][k][1]!=INF)
        {
          ans=max(ans,k);
          int ol=dp[i][j][k][1]+arr[j][0]-arr[j-1][0];
          dp[i][j-1][k+(ol<=arr[j-1][1])][1]=min(dp[i][j-1][k+(ol<=arr[j-1][1])][1],ol);
          int ol2=dp[i][j][k][1]+l-arr[j][0]+arr[i+1][0];
          dp[i+1][j][k+(ol2<=arr[i+1][1])][0]=min(dp[i+1][j][k+(ol2<=arr[i+1][1])][0],ol2);
        }
      }
    }
  }
  cout << ans << endl;
}

int32_t main(){
   

     cin.tie(0); ios::sync_with_stdio(0);
     cout << fixed <<  setprecision(15);
   
   int t=1;//cin>> t;
 
 for(int i=1;i<=t;i++)
 {
  //  cout << "Case #" << i << ": ";
    solve();
 }
 
 return 0;
}

Compilation message (stderr)

ho_t3.cpp:2: warning: ignoring '#pragma optimize ' [-Wunknown-pragmas]
    2 | #pragma optimize ("Bismillahirrahmanirrahim")
      |

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 75 / 75