Submission #633808

#	Time	Username	Problem	Language	Result	Execution time	Memory
633808		Saeed_247	Xylophone (JOI18_xylophone)	C++14	47 / 100	85 ms	548 KiB

xylophone

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

static int A[5010];
int pos[5050];

void solve(int n) {
    int lo = 1, hi = n;
    while (hi - lo > 1) {
        int mid = (lo + hi) / 2;
        if (query(mid, n) == n - 1) {
            lo = mid;
        }
        else {
            hi = mid;
        }
    }
    A[lo] = 1;
    pos[1] = lo;
    if (lo > 1) {
        A[lo - 1] = query(lo - 1, lo) + 1;
        pos[A[lo - 1]] = lo - 1;
    }
    A[lo + 1] = query(lo, lo + 1) + 1;
    pos[A[lo + 1]] = lo + 1;
    for (int i = lo - 2; i >= 1; i--) {
        int diff = query(i, i + 1);
        bool a = (pos[min(A[i + 1] + diff, n + 1)] == 0), b = (pos[min(A[i + 1] - diff, 0)] == 0);
        if (a && b) {
            int x = query(i, i + 2);
            if (max({A[i + 1] + diff, A[i + 1], A[i + 2]}) - min({A[i + 1] + diff, A[i + 1], A[i + 2]}) == x) {
                A[i] = A[i + 1] + diff;
            }
            else {
                A[i] = A[i + 1] - diff;
            }
        }
        else if (a) A[i] = A[i + 1] + diff;
        else A[i] = A[i + 1] - diff;
        pos[A[i]] = i;
    }
    for (int i = lo + 2; i <= n; i++) {
        int diff = query(i - 1, i);
        bool a = (pos[min(A[i - 1] + diff, n + 1)] == 0), b = (pos[min(A[i - 1] - diff, 0)] == 0);
        if (a && b) {
            int x = query(i - 2, i);
            if (max({A[i - 1] + diff, A[i - 1], A[i - 2]}) - min({A[i - 1] + diff, A[i - 1], A[i - 2]}) == x) {
                A[i] = A[i - 1] + diff;
            }
            else {
                A[i] = A[i - 1] - diff;
            }
        }
        else if (a) A[i] = A[i - 1] + diff;
        else A[i] = A[i - 1] - diff;
        pos[A[i]] = i;
    }
    for (int i = 1; i <= n; i++) {
        answer(i, A[i]);
    }
}

• Subtask 1: 11 / 11
• Subtask 2: 36 / 36
• Subtask 3: 0 / 53