Submission #505195

#	Time	Username	Problem	Language	Result	Execution time	Memory
505195		colossal_pepe	Xylophone (JOI18_xylophone)	C++17	0 / 100	1 ms	332 KiB

xylophone

// #include <xylophone.h>
#include <iostream>
#include <vector>
using namespace std;

int n;
vector<int> a, pos;

int query(int s, int t);
void answer(int i, int x);

int find1Pos() {
    int l = 1, r = n;
    while (r - l > 1) {
        int mid = (r + l) / 2;
        if (query(mid, n) == n - 1) l = mid;
        else r = mid - 1;
    }
    if (query(r, n) == n - 1) return r;
    return l;
}

int getVal(int cur, int p, int pp) {
    int d = query(min(cur, p), max(cur, p));
    if (a[p] + d > n or pos[a[p] + d] != -1) {
        return a[p] - d;
    } else if (a[p] - d < 1 or pos[a[p] - d] != -1) {
        return a[p] + d;
    } else {
        int e = query(min(cur, pp), max(cur, pp)), c = 1;
        if (a[p] > a[pp]) c = -1;
        return (e == abs(a[p] - a[pp]) ? a[p] + (c * d) : a[p] - (c * d));
    }
}

void solve(int N) {
    n = N;
    a.resize(n + 1, -1), pos.resize(n + 1, -1);
    pos[1] = find1Pos();
    a[pos[1]] = 1;
    int l = pos[1] - 1;
    while (l >= 1) {
        a[l] = getVal(l, l + 1, l + 2);
        pos[a[l]] = l;
        l--;
    }
    int r = pos[1] + 1;
    while (r <= n) {
        a[r] = getVal(r, r - 1, r - 2);
        pos[a[r]] = r;
        r++;
    }
    for (int i = 1; i <= n; i++) {
        answer(i, a[i]);
    }
}

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