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Submission #804506

# Submission time Handle Problem Language Result Execution time Memory
804506 2023-08-03T09:17:34 Z rnl42 Colors (BOI20_colors) C++14
0 / 100
 1 ms 464 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long

int N;
unordered_set<int> used;

inline int getvalid(int N) {
    int mincur = 0, maxcur = 0;
    int cur = 0;
    int mini = 1, maxi = N-1;
    bool parity = false;
    while (mini <= maxi) {
        int mid = (mini+maxi)>>1;
        int next;
        if (!parity) {
            next = cur+mid;
        } else {
            next = cur-mid;
        }
        mini = mid+1;
        cur = next;
        parity ^= 1;
        mincur = min(mincur, cur);
        maxcur = max(maxcur, cur);
    }
    //assert(maxcur-mincur <= N-1);
    return -mincur;
}

inline bool query(int x) {
    assert(!used.count(x));
    used.insert(x);
    cout << "? " << x+1 << '\n' << flush;
    assert(x >= 0 && x < N);
    bool ret;
    cin >> ret;
    return ret;
}

signed main() {
    //ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    cin >> N;
    int cur = getvalid(N);
    int mini = 1, maxi = N-1;
    query(cur);
    bool parity = false;
    while (mini < maxi) {
        int mid = (mini+maxi)>>1;
        int next;
        if (!parity) {
            next = cur+mid;
        } else {
            next = cur-mid;
        }
        if (used.count(next)) {
            int inter = max(0ll, N/3-10);
            for (; used.count(inter) || used.count(inter+mid); inter++);
            query(inter);
            next = inter+mid;
        }
        if (query(next)) {
            maxi = mid;
        } else {
            mini = mid+1;
        }
        cur = next;
        parity ^= 1;
    }
    cout << "= " << mini << '\n';
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (4 queries)
2 Correct 0 ms 208 KB OK (6 queries)
3 Correct 0 ms 208 KB OK (5 queries)
4 Correct 0 ms 208 KB OK (6 queries)
5 Correct 1 ms 208 KB OK (6 queries)
6 Correct 1 ms 256 KB OK (7 queries)
7 Correct 1 ms 256 KB OK (7 queries)
8 Correct 0 ms 208 KB OK (7 queries)
9 Runtime error 1 ms 464 KB Execution killed with signal 6
10 Halted 0 ms 0 KB -

Subtask #2
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (4 queries)
2 Correct 0 ms 208 KB OK (6 queries)
3 Correct 0 ms 208 KB OK (5 queries)
4 Correct 0 ms 208 KB OK (6 queries)
5 Correct 1 ms 208 KB OK (6 queries)
6 Correct 1 ms 256 KB OK (7 queries)
7 Correct 1 ms 256 KB OK (7 queries)
8 Correct 0 ms 208 KB OK (7 queries)
9 Runtime error 1 ms 464 KB Execution killed with signal 6
10 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (4 queries)
2 Correct 0 ms 208 KB OK (6 queries)
3 Correct 0 ms 208 KB OK (5 queries)
4 Correct 0 ms 208 KB OK (6 queries)
5 Correct 1 ms 208 KB OK (6 queries)
6 Correct 1 ms 256 KB OK (7 queries)
7 Correct 1 ms 256 KB OK (7 queries)
8 Correct 0 ms 208 KB OK (7 queries)
9 Runtime error 1 ms 464 KB Execution killed with signal 6
10 Halted 0 ms 0 KB -

Subtask #4
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (4 queries)
2 Correct 0 ms 208 KB OK (6 queries)
3 Correct 0 ms 208 KB OK (5 queries)
4 Correct 0 ms 208 KB OK (6 queries)
5 Correct 1 ms 208 KB OK (6 queries)
6 Correct 1 ms 256 KB OK (7 queries)
7 Correct 1 ms 256 KB OK (7 queries)
8 Correct 0 ms 208 KB OK (7 queries)
9 Runtime error 1 ms 464 KB Execution killed with signal 6
10 Halted 0 ms 0 KB -

Subtask #5
0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (4 queries)
2 Correct 0 ms 208 KB OK (6 queries)
3 Correct 0 ms 208 KB OK (5 queries)
4 Correct 0 ms 208 KB OK (6 queries)
5 Correct 1 ms 208 KB OK (6 queries)
6 Correct 1 ms 256 KB OK (7 queries)
7 Correct 1 ms 256 KB OK (7 queries)
8 Correct 0 ms 208 KB OK (7 queries)
9 Runtime error 1 ms 464 KB Execution killed with signal 6
10 Halted 0 ms 0 KB -