Submission #1014779

#	Time	Username	Problem	Language	Result	Execution time	Memory
1014779		MilosMilutinovic	Shortcut (IOI16_shortcut)	C++14	71 / 100	2041 ms	1884 KiB

shortcut

#include "shortcut.h"
#include <bits/stdc++.h>
 
using namespace std;
 
long long find_shortcut(int n, vector<int> l, vector<int> d, int c) {
  vector<long long> x(n);
  for (int i = 1; i < n; i++) {
    x[i] = x[i - 1] + l[i - 1];
  }
  const long long inf = (long long) 1e18;
  auto Check = [&](long long diam) {
    long long xl = -inf, xr = inf;
    long long yl = -inf, yr = inf;
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < n; j++) {
        if (i == j) {
          continue;
        }
        if (d[i] + d[j] + x[j] - x[i] <= diam) {
          continue;
        }
        long long r = diam - d[i] - d[j] - c;
        if (r < 0) {
          return false;
        }
        xl = max(xl, x[i] + x[j] - r);
        xr = min(xr, x[i] + x[j] + r);
        yl = max(yl, x[j] - r - x[i]);
        yr = min(yr, x[j] + r - x[i]);
      }
    }
    int plx = n, prx = n - 1, ply = 0, pry = -1;
    for (int i = 0; i < n; i++) {
      while (plx > 0 && x[i] + x[plx - 1] >= xl) {
        plx--;
      }
      while (prx >= 0 && x[i] + x[prx] > xr) {
        prx--;
      }
      while (ply < n && x[ply] - x[i] < yl) {
        ply++;
      }
      while (pry + 1 < n && x[pry + 1] - x[i] <= yr) {
        pry++;
      }
      int L = max({i + 1, plx, ply}), R = min(prx, pry);
      if (L <= R) {
        return true;
      }
    }
    return false;
  };  
  long long low = 0, high = inf, ans = 0;
  while (low <= high) {
    long long mid = (low + high) >> 1;
    if (Check(mid)) {
      ans = mid;
      high = mid - 1;
    } else {
      low = mid + 1;
    }
  }
  return ans;
}

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 7 / 7
• Subtask 5: 33 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3