# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1015932 | hotboy2703 | 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.
#include "prize.h"
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define pll pair <ll,ll>
#define fi first
#define se second
#define MP make_pair
#define sz(a) (ll((a).size()))
#define BIT(mask,i) (((mask) >> (i))&1)
#define MASK(i) (1LL << (i))
const ll MAXN = 2e5+100;
pll a[MAXN];
ll ans = -1;
ll req = 0;
void query(ll i){
if (a[i].fi==-1){
vector <int> tmp = ask(i);
a[i] = MP(tmp[0],tmp[1]);
if (a[i].fi+a[i].se==0)ans = i;
}
}
void solve(ll l,ll r,ll l1,ll r1){
ll k=r1-l1;
if (k==0)return;
ll mid = (l + r) >> 1;
ll id = -1;
for (ll i = 0;i < k;i ++){
ll cur_mid = mid + ((i+1)/2) * (i%2?1:-1);
query(cur_mid);
if (a[cur_mid].fi+a[cur_mid].se==req){
id = i;
break;
}
}
if (id==-1)return;
ll mid_l,mid_r;
ll L,R;
if (id%2){
mid_r = mid + ((id+1)/2);
mid_l = mid - ((id-1)/2);
R = a[mid_r].fi;
L = R-id;
}
else{
mid_r = mid + (id/2);
mid_l = mid - (id/2);
L = a[mid_l].fi;
R = L+id;
}
solve(l,mid_l-1,l,L);
solve(mid_r+1,r,R,r);
}
int find_best(int n) {
memset(a,-1,sizeof a);
// req = 3;
for (ll i = 0;i < min(500,n);i ++){
query(i);
req = max(a[i].fi+a[i].se,req);
}
solve(0,n-1,req);
return ans;
}