# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
761691 | minhcool | The Big Prize (IOI17_prize) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
//#define local
#ifndef local
#include "prize.h"
#endif
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
//#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
const int N = 3e5 + 5;
const int oo = 1e18 + 7, mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l, int r){
int temp = rng() % (r - l + 1);
return abs(temp) + l;
}
#ifdef local
int n, arr[N];
vector<int> ask(int x){
vector<int> v;
int num = 0;
for(int i = x - 1; i >= 0; i--) num += (arr[i] < arr[x]);
v.pb(num);
num = 0;
for(int i = x + 1; i < n; i++) num += (arr[i] < arr[x]);
v.pb(num);
return v;
}
#endif
ii gett[N];
ii cal(int x){
if(gett[x].fi || gett[x].se) return gett[x];
vector<int> v = ask(x);
return gett[x] = {v[0], v[1]};
}
int find_best(int n){
if(n <= 1000){
// exit(0);
for(int i = 0; i < n; i++){
ii temp = cal(i);
// cout << temp.fi << " " << temp.se << "\n";
if(!(temp.fi + temp.se)) return i;
}
exit(0);
}
int maxi = -oo;
for(int itr = 1; itr <= 30; itr++){
int pos = rnd(0, n - 1);
ii temp = cal(pos);
maxi = max(maxi, temp.fi + temp.se);
}
int lst = -1, num = 0;
while(1){
int le = lst + 1, ri = n - 1;
assert(le < n && ri < n);
num++;
int troll = 0;
while(le < ri){
int mid = (le + ri) >> 1;
if(!troll){
mid = min(mid, le + 500);
troll = 1;
}
assert(le < n && ri < n && mid < n);
ii temp = cal(mid);
if((temp.fi + temp.se) != maxi){
if(!(temp.fi + temps.se)) return mid;
ri = mid;
}
else if(temp.fi >= num) ri = mid;
else le = mid + 1;
}
ii temp = cal(le);
if(!(temp.fi + temp.se)) return le;
lst = le;
}
assert(0);
}
//#define local
#ifdef local
void process(){
cin >> n;
for(int i = 0; i < n; i++) cin >> arr[i];
cout << find_best(n) << "\n";
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
process();
}
#endif