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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#688718 | #8939. Permutation | lqh2024 | WA | 1ms | 3748kb | C++20 | 2.5kb | 2024-10-30 13:01:22 | 2024-10-30 13:01:22 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
#define int long long
mt19937_64 rng(time(0));
template <class T, class ... A> void debug(T t, A ... a) {
cerr << "[" << t, ((cerr << ", " << a), ...), cerr << "]\n";
}
void QAQ() {
int n;
cin >> n;
vector<int> a(n + 1);
auto query = [&](int l, int r, int x = -1) {
cout << "? " << l << " " << r << endl;
return cin >> x, x;
};
auto answer = [&](int n) {
cout << "! " << n << endl;
};
int lst = query(1, n);
auto F = [&](auto && self, int l, int r) {
if (l >= r) return answer(l);
if (l + 1 == r) {
if (l == lst) return answer(r);
else return answer(l);
}
int m = l + r >> 1, tmp = rng() % 2;
if (l + 2 == r) {
m = l;
tmp = query(m + 1, r);
if (l == lst) {
if (tmp == r) return answer(m + 1);
else return answer(r);
} else {
if (tmp == lst) return answer(tmp == r ? r - 1 : r);
else return answer(l);
}
}
if (tmp) {
tmp = query(l, m);
if (tmp == lst) {
lst = tmp;
return self(self, l, m);
} else if (lst <= m) {
lst = query(m + 1, r);
return self(self, m + 1, r);
} else {
int t = query(m + 1, r);
if (t == lst) {
lst = t;
return self(self, m + 1, r);
} else {
lst = tmp;
return self(self, l, m);
}
}
} else {
tmp = query(m + 1, r);
if (tmp == lst) {
lst = tmp;
return self(self, m + 1, r);
} else if (lst > m) {
lst = query(l, m);
return self(self, l, m);
} else {
int t = query(l, m);
if (t == lst) {
lst = t;
return self(self, l, m);
} else {
lst = tmp;
return self(self, m + 1, r);
}
}
}
};
F(F, 1, n);
}
signed main() {
cin.tie(0) -> sync_with_stdio(0);
int t = 1;
cin >> t;
for (cout << fixed << setprecision(12); t--; QAQ());
}
Details
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Test #1:
score: 100
Accepted
time: 1ms
memory: 3748kb
input:
3 5 3 5 2 6 6 3 5 3 4 3 3
output:
? 1 5 ? 4 5 ? 1 3 ! 4 ? 1 6 ? 1 3 ? 4 6 ? 2 3 ! 2 ? 1 4 ? 3 4 ! 4
result:
ok Correct (3 test cases)
Test #2:
score: -100
Wrong Answer
time: 0ms
memory: 3688kb
input:
10000 10 2 9 2 3 5 10 10 5 10 9 7
output:
? 1 10 ? 6 10 ? 1 5 ? 1 3 ? 4 5 ! 4 ? 1 10 ? 1 5 ? 6 10 ? 9 10 ? 6 8 ? 7 8
result:
wrong answer Too many queries , n = 10 , now_q 6 (test case 2)