Submission #379265

#	Time	Username	Problem	Language	Result	Execution time	Memory
379265		qwerty234	Xylophone (JOI18_xylophone)	C++14	100 / 100	83 ms	524 KiB

xylophone

#include <bits/stdc++.h>
#include "xylophone.h"
#define ll long long
#define fi first
#define se second
#define pb push_back

using namespace std;

const int MAXN = 5e5 + 10, inf = 2e9;

void solve(int n) {
  vector <int> b; b.assign(n, 0);
  vector <bool> vis(n + 1, false);
  int l = 0, r = n - 1, posn = n - 1;
  while (l <= r) {
    int m = (l + r) / 2;
    int tmp = query(1, m + 1);
    if (tmp < n - 1) {
      l = m + 1;
    } else {
      posn = min(posn, m);
      r = m - 1;
    }
  }
  b[posn] = n; vis[n] = true;
	if (posn != n - 1) {
		int tmp = query(posn + 1, posn + 2);
		b[posn + 1] = n - tmp;
	}
	if (posn != 0) {
		int tmp = query(posn, posn + 1);
		b[posn - 1] = n - tmp;
	}
  for (int i = posn + 2; i < n; i++) {
    int x, y, tmp = query(i, i + 1);
    x = b[i - 1] + tmp; y = b[i - 1] - tmp;
    if (x > n || vis[x]) {
      b[i] = y;
    } else if (y < 1 || vis[y]) {
      b[i] = x;
    } else {
      int tmp = query(i - 1, i + 1);
			if (b[i - 2] < b[i - 1]) {
				if (tmp == x - b[i - 2]) {
					b[i] = x;
				} else {
					b[i] = y;
				}
			} else {
				if (tmp == b[i - 2] - y) {
					b[i] = y;
				} else {
					b[i] = x;
				}
			}
    }
    vis[b[i]] = true;
  }

  for (int i = posn - 2; i >= 0; i--) {
    int x, y, tmp = query(i + 1, i + 2);
    x = b[i + 1] + tmp; y = b[i + 1] - tmp;
    if (x > n || vis[x]) {
      b[i] = y;
    } else if (y < 1 || vis[y]) {
      b[i] = x;
    } else {
			int tmp = query(i + 1, i + 3);
			if (b[i + 2] < b[i + 1]) {
				if (tmp == x - b[i + 2]) {
					b[i] = x;
				} else {
					b[i] = y;
				}
			} else {
				if (tmp == b[i + 2] - y) {
					b[i] = y;
				} else {
					b[i] = x;
				}
			}
    }
    vis[b[i]] = true;
  }

  for (int i = 0; i < n; i++) {
    answer(i + 1, b[i]);
    // cout << b[i] << " ";
  }
}

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