Submission #1113499

#	Time	Username	Problem	Language	Result	Execution time	Memory
1113499		epicci23	The Big Prize (IOI17_prize)	C++17	90 / 100	187 ms	1908 KiB

prize

#include "bits/stdc++.h"
#include "prize.h"
//#define int long long
#define all(v) v.begin() , v.end()
#define sz(a) (int)a.size()
using namespace std;
 
int suf = -1;
vector<int> Cache={-1,-1};
map<int,vector<int>> dp;
 
vector<int> Ask(int i){
  if(dp.count(i)) return dp[i];
  return dp[i]=ask(i);
}
 
int ask_all(int l,int r){
  for(int i=l;i<=r;i++){
    vector<int> x = Ask(i);
    if(x[0] + x[1] == 0) return i;
    if(x[1] == suf) Cache=x;
    else suf--;
  }
  return -23;
}
 
int Learn(int l,int r){
  if(l>r) return -1;
  if(l==r){
    auto u = Ask(l);
    if(u[0] + u[1] == 0) return l;
    if(u[1] == suf) Cache=u;
    else suf--;
    return -1;
  }
  auto X = Ask(r);
  if(X[0] + X[1] == 0) return r;
  if(X[1] == suf) return -1;
  int mid = (l + r) / 2;
  auto u = Ask(mid);
  if(u[0] + u[1] == 0) return mid;
  if(u[1] == suf) return Learn(mid + 1,r - 1);
  int lf = Learn(l,mid - 1);
  if(lf != -1) return lf;
  if(u[1]==suf) Cache=u;
  else suf--;
  if(X[1] == suf - (Cache[0]+Cache[1] > X[0] + X[1]) ) return -1;
  int hm = Learn(mid+1,r-1);
  if(hm !=- 1) return hm;
  if(X[1] == suf) Cache = X;
  else suf--;
  return -1;
}
 
int find_best(int n){
  if(n<=1000) return ask_all(0,n-1);
  int art=0;
  for(int i=0;i<=500;i++){
  	if(art==5) return Learn(i,n-1);
    vector<int> x = Ask(i);
    if(x[0]+x[1]==0) return i;
    if(x[0]+x[1]>Cache[0]+Cache[1]) art++;
    if(x[0]+x[1]>=Cache[0]+Cache[1]){
      Cache=x;
      suf=Cache[1];
    }
    else suf--;
  }
  return Learn(501,n-1);
}

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80