Submission #776064

#	Time	Username	Problem	Language	Result	Execution time	Memory
776064		anha3k25cvp	Xylophone (JOI18_xylophone)	C++14	100 / 100	66 ms	444 KiB

xylophone

#include <bits/stdc++.h>
#include "xylophone.h"

using namespace std;

void solve(int n) {
    int lo = 1, hi = n;
    vector <int> a(n + 1, 0), vis(n + 1, 0);
    while (lo < hi) {
        int mid = (lo + hi + 1) / 2, val = query(mid, n);
        if (val == n - 1)
            lo = mid;
        else
            hi = mid - 1;
    }
    a[lo] = 1;
    vis[1] = 1;
    if (lo > 1) {
        int val = query(lo - 1, lo);
        a[lo - 1] = val + 1;
        vis[val + 1] = 1;
        for (int i = lo - 2; i > 0; i --) {
            val = query(i, i + 1);
            vector <int> g;
            if (a[i + 1] - val > 0 && !vis[a[i + 1] - val])
                g.push_back(a[i + 1] - val);
            if (a[i + 1] + val <= n && !vis[a[i + 1] + val])
                g.push_back(a[i + 1] + val);
            if (g.size() == 1) {
                a[i] = g[0];
                vis[a[i]] = 1;
            }
            else {
                int val_ = max({g[0], a[i + 1], a[i + 2]}) - min({g[0], a[i + 1], a[i + 2]});
                if (val_ == query(i, i + 2)) {
                    a[i] = g[0];
                    vis[a[i]] = 1;
                }
                else {
                    a[i] = g[1];
                    vis[a[i]] = 1;
                }
            }
        }
    }
    int val = query(lo, lo + 1);
    a[lo + 1] = val + 1;
    vis[val + 1] = 1;
    for (int i = lo + 2; i <= n; i ++) {
        val = query(i - 1, i);
        vector <int> g;
        if (a[i - 1] - val > 0 && !vis[a[i - 1] - val])
            g.push_back(a[i - 1] - val);
        if (a[i - 1] + val <= n && !vis[a[i - 1] + val])
            g.push_back(a[i - 1] + val);
        if (g.size() == 1) {
            a[i] = g[0];
            vis[a[i]] = 1;
        }
        else {
            int val_ = max({g[0], a[i - 1], a[i - 2]}) - min({g[0], a[i - 1], a[i - 2]});
            if (val_ == query(i - 2, i)) {
                a[i] = g[0];
                vis[a[i]] = 1;
            }
            else {
                a[i] = g[1];
                vis[a[i]] = 1;
            }
        }
    }
    for (int i = 1; i <= n; i ++)
        answer(i, a[i]);
}

• Subtask 1: 11 / 11
• Subtask 2: 36 / 36
• Subtask 3: 53 / 53