Submission #1306895

#	Time	Username	Problem	Language	Result	Execution time	Memory
1306895		teamcuddlepie	Xylophone (JOI18_xylophone)	C++20	Compilation error	0 ms	0 KiB

xylophone

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

// These are provided by the grader (do NOT implement them)
int query(int l, int r);
void answer(vector<int> A);

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;

    vector<int> d(N - 1);

    // 1) Adjacent differences
    for (int i = 0; i < N - 1; i++) {
        d[i] = query(i + 1, i + 2);
    }

    // sign[i] = +1 if A[i+1] > A[i], -1 otherwise
    vector<int> sign(N - 1);
    sign[0] = 1; // arbitrarily assume increasing at first

    // 2) Determine directions using triples
    for (int i = 0; i < N - 2; i++) {
        int t = query(i + 1, i + 3);
        if (t == d[i] + d[i + 1]) {
            // same direction
            sign[i + 1] = sign[i];
        } else {
            // direction flips
            sign[i + 1] = -sign[i];
        }
    }

    // 3) Build relative values
    vector<int> b(N);
    b[0] = 0;
    for (int i = 1; i < N; i++) {
        b[i] = b[i - 1] + sign[i - 1] * d[i - 1];
    }

    // 4) Normalize to permutation 1..N
    int mn = *min_element(b.begin(), b.end());
    for (int i = 0; i < N; i++) {
        b[i] -= mn;
    }

    // Now b contains values from 0..N-1 (in some order)
    vector<int> A(N);
    for (int i = 0; i < N; i++) {
        A[i] = b[i] + 1;
    }

    // Output answer
    answer(A);
    return 0;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccyDwWeo.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccOK9qIV.o:xylophone.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccOK9qIV.o: in function `main':
xylophone.cpp:(.text.startup+0x283): undefined reference to `answer(std::vector<int, std::allocator<int> >)'
/usr/bin/ld: /tmp/ccyDwWeo.o: in function `main':
grader.cpp:(.text.startup+0x30): undefined reference to `solve(int)'
collect2: error: ld returned 1 exit status