Submission #379258

#	Time	Username	Problem	Language	Result	Execution time	Memory
379258		qwerty234	Xylophone (JOI18_xylophone)	C++14	0 / 100	1 ms	492 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;
 
// int n;
// vector <int> a;
 
// int query(int s, int t) {
//   // cout << "plus" << endl;
//   s--; t--;
//   int mx = a[s], mn = a[s];
//   for (int i = s; i <= t; i++) mx = max(mx, a[i]), mn = min(mn, a[i]);
//   return mx - mn;
// }
 
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;
 
  int cnt = 1;
 
  for (int i = posn + 1; 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 j = i - 1;
      while (b[j] <= x)
        j--;
      int tmp = query(j + 1, i + 1);
      if (tmp == b[j] - x) {
        b[i] = x;
      } else {
        b[i] = y;
      }
    }
    vis[b[i]] = true;
    cnt++;
    if (cnt == n - 1) {
      int t1;
      for (int j = 1; j <= n; j++)
        if (!vis[j])
          t1 = j;
      for (int j = 0; j < n; j++)
        if (b[j] == 0)
          b[j] = t1;
      break;
    }
  }
 
  for (int i = posn - 1; 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 j = i + 1;
      while (b[j] <= x)
        j++;
      int tmp = query(i + 1, j + 1);
      if (tmp == b[j] - x) {
        b[i] = x;
      } else {
        b[i] = y;
      }
    }
    vis[b[i]] = true;
    cnt++;
    if (cnt == n - 1) {
      int t1;
      for (int j = 1; j <= n; j++)
        if (!vis[j])
          t1 = j;
      for (int j = 0; j < n; j++)
        if (b[j] == 0)
          b[j] = t1;
      break;
    }
  }
 
  for (int i = 0; i < n; i++) {
    answer(i + 1, b[i]);
    // cout << b[i] << " ";
  }
}

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:100:16: warning: 't1' may be used uninitialized in this function [-Wmaybe-uninitialized]
  100 |           b[j] = t1;
xylophone.cpp:68:16: warning: 't1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   68 |           b[j] = t1;

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