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ID	Problem	Submitter	Result	Time	Memory	Language	File size	Submit time	Judge time
#548372	#6394. Turn on the Light	pandapythoner^#	AC ✓	1ms	3716kb	C++23	2.0kb	2024-09-05 17:38:52	2024-09-05 17:38:52

Judging History

你现在查看的是最新测评结果

[2024-09-05 17:38:52]
评测

测评结果：AC
用时：1ms
内存：3716kb

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[2024-09-05 17:38:52]
提交

answer

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;

#define len(a) int((a).size())
#define all(a) begin(a), end(a)
#define rep(i, n) for (int i = 0; i < (n); i++)

signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    int n;
    cin >> n;

#ifdef LOCAL
    int x = rand() % n;
    cerr << "x=" << x << endl;
    int cur_ans_ = 0;
    set<int> was;
#endif

    auto query = [&](int pos) {
        cout << "? " << pos + 1 << endl;
#ifdef LOCAL
        assert(was.insert(pos).second);
        if (pos < x) {
            cur_ans_++;
        } else if (pos > x) {
            cur_ans_--;
        }
        return abs(cur_ans_);
#else
        int res;
        cin >> res;
        return res;
#endif
        };

    int q0 = query(0);
    if (q0 == 0) {
        cout << "! 1" << endl;
        return 0;
    }
    int q1 = query(1);
    if (q1 == q0) {
        cout << "! 2" << endl;
        return 0;
    }
    assert(q1 == 2);

    int l = 2, r = n;
    while (r - l > 1) {
        int mid = (l + r) / 2;
        int cur = query(mid);
        if (cur == 2) {
            cout << "! " << mid + 1 << endl;
#ifdef LOCAL
            assert(mid == x);
#endif
            return 0;
        }

        // cerr << "[" << l << ", " << r << "]: " << mid << endl;
        assert(r - l > 1);
        if (cur == 1) {
            r = mid;
            if (r - l == 1) break;
            int tmp = query(l);
            if (tmp == 1) {
                cout << "! " << l + 1 << endl;
                return 0;
            }
            assert(tmp == 2);
            l++;
        } else {
            assert(cur == 3);
            l = mid + 1;
            if (r - l == 1) break;
            int tmp = query(r - 1);
            if (tmp == 3) {
                cout << "! " << r << endl;
                return 0;
            }
            assert(tmp == 2);
            r--;
        }
    }
    cout << "! " << r << endl;
#ifdef LOCAL
    assert(l == x);
#endif
}

Source code, Language: C++23

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100

Accepted

time: 0ms

memory: 3660kb

input:

3
1
2

output:

? 1
? 2
! 3

result:

ok Correct position at 3

Test #2:

score: 0

Accepted

time: 0ms

memory: 3708kb

input:

output:

? 1
? 2
? 7
? 3
? 5
! 4

result:

ok Correct position at 4

Test #3:

score: 0

Accepted

time: 1ms

memory: 3668kb

input:

output:

? 1
? 2
? 6
? 9
? 8
! 8

result:

ok Correct position at 8

Test #4:

score: 0

Accepted

time: 1ms

memory: 3592kb

input:

output:

? 1
? 2
? 6
? 3
? 5
! 5

result:

ok Correct position at 5

Test #5:

score: 0

Accepted

time: 0ms

memory: 3660kb

input:

output:

? 1
? 2
? 5
? 7
! 6

result:

ok Correct position at 6

Test #6:

score: 0

Accepted

time: 0ms

memory: 3708kb

input:

output:

? 1
? 2
? 5
? 3
! 3

result:

ok Correct position at 3

Test #7:

score: 0

Accepted

time: 0ms

memory: 3596kb

input:

output:

? 1
? 2
? 4
! 5

result:

ok Correct position at 5

Test #8:

score: 0

Accepted

time: 1ms

memory: 3584kb

input:

output:

? 1
? 2
? 4
! 4

result:

ok Correct position at 4

Test #9:

score: 0

Accepted

time: 1ms

memory: 3592kb

input:

3
1
1

output:

? 1
? 2
! 2

result:

ok Correct position at 2

Test #10:

score: 0

Accepted

time: 0ms

memory: 3716kb

input:

2
1
1

output:

? 1
? 2
! 2

result:

ok Correct position at 2

Test #11:

score: 0

Accepted

time: 1ms

memory: 3668kb

input:

1
0

output:

? 1
! 1

result:

ok Correct position at 1

Test #12:

score: 0

Accepted

time: 1ms

memory: 3592kb

input:

output:

result:

ok Correct position at 50

Test #13:

score: 0

Accepted

time: 1ms

memory: 3660kb

input:

output:

result:

ok Correct position at 765669

Test #14:

score: 0

Accepted

time: 1ms

memory: 3628kb

input:

output:

result:

ok Correct position at 265671

Test #15:

score: 0

Accepted

time: 1ms

memory: 3684kb

input:

output:

result:

ok Correct position at 515670

Test #16:

score: 0

Accepted

time: 1ms

memory: 3704kb

input:

output:

result:

ok Correct position at 15673

Test #17:

score: 0

Accepted

time: 0ms

memory: 3648kb

input:

output:

result:

ok Correct position at 765666

Test #18:

score: 0

Accepted

time: 1ms

memory: 3628kb

input:

output:

result:

ok Correct position at 265670

Test #19:

score: 0

Accepted

time: 1ms

memory: 3660kb

input:

output:

result:

ok Correct position at 515668

Test #20:

score: 0

Accepted

time: 1ms

memory: 3588kb

input:

output:

result:

ok Correct position at 15673

Test #21:

score: 0

Accepted

time: 0ms

memory: 3668kb

input:

output:

result:

ok Correct position at 765663

Test #22:

score: 0

Accepted

time: 1ms

memory: 3648kb

input:

output:

result:

ok Correct position at 43

Test #23:

score: 0

Accepted

time: 1ms

memory: 3712kb

input:

output:

result:

ok Correct position at 51

Test #24:

score: 0

Accepted

time: 1ms

memory: 3584kb

input:

output:

result:

ok Correct position at 51

Test #25:

score: 0

Accepted

time: 0ms

memory: 3648kb

input:

output:

result:

ok Correct position at 51

Test #26:

score: 0

Accepted

time: 1ms

memory: 3632kb

input:

output:

result:

ok Correct position at 999781

Test #27:

score: 0

Accepted

time: 0ms

memory: 3588kb

input:

output:

result:

ok Correct position at 999980

Test #28:

score: 0

Accepted

time: 1ms

memory: 3644kb

input:

output:

result:

ok Correct position at 999979

Test #29:

score: 0

Accepted

time: 1ms

memory: 3644kb

input:

output:

result:

ok Correct position at 999978

Test #30:

score: 0

Accepted

time: 1ms

memory: 3648kb

input:

output:

result:

ok Correct position at 499947

Test #31:

score: 0

Accepted

time: 0ms

memory: 3664kb

input:

output:

result:

ok Correct position at 500070

Test #32:

score: 0

Accepted

time: 1ms

memory: 3644kb

input:

output:

result:

ok Correct position at 500076

Test #33:

score: 0

Accepted

time: 0ms

memory: 3652kb

input:

output:

result:

ok Correct position at 499965

Test #34:

score: 0

Accepted

time: 1ms

memory: 3712kb

input:

output:

result:

ok Correct position at 20

Test #35:

score: 0

Accepted

time: 1ms

memory: 3588kb

input:

output:

result:

ok Correct position at 20

Test #36:

score: 0

Accepted

time: 0ms

memory: 3648kb

input:

output:

result:

ok Correct position at 20

Test #37:

score: 0

Accepted

time: 1ms

memory: 3660kb

input:

output:

result:

ok Correct position at 20

Test #38:

score: 0

Accepted

time: 0ms

memory: 3572kb

input:

output:

result:

ok Correct position at 8845

Test #39:

score: 0

Accepted

time: 1ms

memory: 3640kb

input:

output:

result:

ok Correct position at 985397

Test #40:

score: 0

Accepted

time: 0ms

memory: 3564kb

input:

output:

result:

ok Correct position at 485399

Test #41:

score: 0

Accepted

time: 1ms

memory: 3624kb

input:

output:

result:

ok Correct position at 735398

Test #42:

score: 0

Accepted

time: 0ms

memory: 3576kb

input:

output:

result:

ok Correct position at 1000000

Test #43:

score: 0

Accepted

time: 1ms

memory: 3588kb

input:

1000000
0

output:

? 1
! 1

result:

ok Correct position at 1