Submission #255761

#	Time	Username	Problem	Language	Result	Execution time	Memory
255761		IgorI	Xylophone (JOI18_xylophone)	C++17	Compilation error	0 ms	0 KiB

xylophone

#include <bits/stdc++.h>

#define all(x) (x).begin(), (x).end()

using namespace std;

typedef long long ll;

int n;

#ifdef LOCAL
int query(int l, int r)
{
    cout << "? " << l << " " << r << endl;
    int x;
    cin >> x;
    return x;
}

void answer(int i, int x)
{
    cout << "! " << i << " " << x << endl;
}
#endif // LOCAL

int okay(vector<int> q)
{
    int pos1 = 0, posn = 0;
    vector<int> cnt(n + 1);
    for (int i = 1; i <= n; i++)
    {
        if (q[i] < 1 || q[i] > n) return 0;
        cnt[q[i]]++;
        if (cnt[q[i]] == 2) return 0;
        if (q[i] == 1) pos1 = i;
        if (q[i] == n) posn = i;
    }
    return pos1 < posn;
}

void solve(int n0)
{
    n = n0;
    vector<int> a(n), b(n);
    for (int i = 1; i + 1 <= n; i++)
    {
        a[i] = query(i, i + 1);
    }
    for (int i = 1; i + 2 <= n; i++)
    {
        b[i] = query(i, i + 2);
    }
    vector<int> dir(n);
    dir[1] = 1;
    for (int i = 1; i + 2 <= n; i++)
    {
        if (b[i] == a[i] + a[i + 1]) dir[i + 1] = dir[i];
        else dir[i + 1] = dir[i] * (-1);
    }
    vector<vector<int> > ans;
    for (int i = 1; i <= n; i++)
    {
        vector<int> q(n + 1);
        q[1] = i;
        q[2] = dir[1] * a[1] + q[1];
        for (int j = 3; j <= n; j++)
        {
            q[j] = q[j - 1] + dir[j - 1] * a[j - 1];
        }
        if (okay(q)) ans.push_back(q);
    }
    for (int i = 1; i < n; i++) dir[i] *= -1;
    for (int i = 1; i <= n; i++)
    {
        vector<int> q(n + 1);
        q[1] = i;
        q[2] = dir[1] * a[1] + q[1];
        for (int j = 3; j <= n; j++)
        {
            q[j] = q[j - 1] + dir[j - 1] * a[j - 1];
        }
        if (okay(q)) ans.push_back(q);
    }
    for (auto e : ans)
    {
        for (int i = 1; i <= n; i++)
        {
            answer(i, e[i]);
        }
    }
}

#ifdef LOCAL
int main()
{
    int n;
    cin >> n;
    solve(n);
}
#endif // LOCAL

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:47:16: error: 'query' was not declared in this scope
         a[i] = query(i, i + 1);
                ^~~~~
xylophone.cpp:51:16: error: 'query' was not declared in this scope
         b[i] = query(i, i + 2);
                ^~~~~
xylophone.cpp:88:13: error: 'answer' was not declared in this scope
             answer(i, e[i]);
             ^~~~~~
xylophone.cpp:88:13: note: suggested alternative: 'ans'
             answer(i, e[i]);
             ^~~~~~
             ans