#include "prize.h"
#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#define pii pair<int,int>
#define fs first
#define sc second
mt19937 seed(time(NULL));
#define rnd(l,r) uniform_int_distribution<int>(l,r)(seed)
#ifdef LOCAL
const int lim = 3;
const int dt = 5;
#else
const int lim = 5000;
const int dt = 470;
#endif
const int mxn = 2e5+10;
pii dp[mxn];
int N;
int big = 1e9;
int ans = 0;
bool done = false;
int C = 0;
ordered_set<int> st;
pii rng;
pii req(int p){
if(dp[p].fs != -1)return dp[p];
C++;
assert(C<=10000);
auto re = ask(p);
return (dp[p] = pii(re[0],re[1]));
}
int check(int p){
auto re = req(p);
if(!re.fs&&!re.sc)return 0;
else if(N-re.fs-re.sc == big)return 2;
else if(re.fs+re.sc == 1){
if(re.fs == 1)rng.sc = p-1;
else rng.sc = p+1;
}
else{
st.insert(p);
return 1;
}
}
deque<pii> q;
void calc(){
if(done)return;
int l,r;
if(rnd(0,1)){
auto [a,b] = q.front();q.pop_front();
l = a,r = b;
}
else{
auto [a,b] = q.back();q.pop_back();
l = a,r = b;
}
l = max(l,rng.fs);r = min(r,rng.sc);
cerr<<"DFS: "<<l<<','<<r<<endl;
while(l<=r){
if(!check(l)){
ans = l;
done = true;
return;
}
else if(check(l) == 1){
l++;
}
else break;
}
while(l<=r){
if(!check(r)){
ans = r;
done = true;
return;
}
else if(check(r) == 1){
r--;
}
else break;
}
if(l>=r)return;
int cnt = req(r).fs+req(l).sc-(N-big);
if(!cnt)return;
cerr<<"CHECK: "<<l<<','<<r<<','<<cnt<<endl;
assert(cnt>0);
int mid = (l+r+1)>>1;
if(check(mid) == 0){
ans = mid;
done = true;
return;
}
if(l == r)return;
if(l != mid)q.push_back(pii(l,mid));
if(mid != r)q.push_back(pii(mid,r));
return;
}
int find_best(int nn) {
N = nn;
int pt = 0;
for(int i = 1;i*i<2e5;i++)pt = i;
cerr<<pt<<endl;
for(auto &i:dp)i = pii(-1,-1);
if(N<=lim){
for(int i = 0;i<N;i++){
auto tmp = req(i);
if(!tmp.fs&&!tmp.sc)return i;
}
assert(false);
return 0;
}
vector<int> perm;
for(int i = 0;i<N;i++)perm.push_back(i);
shuffle(perm.begin(),perm.end(),seed);
for(int i = 0;i<dt;i++){
auto tmp = req(perm[i]);
big = min(big,N-tmp.fs-tmp.sc);
if(!tmp.fs&&!tmp.sc){
return perm[i];
}
}
cerr<<"BIG: "<<big<<endl;
q.push_back(pii(0,N-1));
rng = pii(0,N-1);
while(!q.empty()&&!done)calc();
if(!done)exit(0);
return ans;
}
Compilation message
prize.cpp: In function 'int check(int)':
prize.cpp:53:1: warning: control reaches end of non-void function [-Wreturn-type]
53 | }
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
3024 KB |
Output is correct |
2 |
Correct |
6 ms |
3024 KB |
Output is correct |
3 |
Correct |
6 ms |
3024 KB |
Output is correct |
4 |
Correct |
5 ms |
3024 KB |
Output is correct |
5 |
Correct |
6 ms |
3024 KB |
Output is correct |
6 |
Correct |
5 ms |
3020 KB |
Output is correct |
7 |
Correct |
7 ms |
3024 KB |
Output is correct |
8 |
Correct |
5 ms |
3020 KB |
Output is correct |
9 |
Correct |
5 ms |
3024 KB |
Output is correct |
10 |
Correct |
5 ms |
3024 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
3024 KB |
Output is correct |
2 |
Correct |
6 ms |
3024 KB |
Output is correct |
3 |
Correct |
6 ms |
3024 KB |
Output is correct |
4 |
Correct |
6 ms |
3024 KB |
Output is correct |
5 |
Correct |
5 ms |
3024 KB |
Output is correct |
6 |
Correct |
5 ms |
3024 KB |
Output is correct |
7 |
Correct |
5 ms |
3024 KB |
Output is correct |
8 |
Correct |
6 ms |
3024 KB |
Output is correct |
9 |
Correct |
5 ms |
3024 KB |
Output is correct |
10 |
Correct |
6 ms |
3024 KB |
Output is correct |
11 |
Runtime error |
16 ms |
5580 KB |
Execution killed with signal 11 |
12 |
Halted |
0 ms |
0 KB |
- |