Submission #1289979

#	Time	Username	Problem	Language	Result	Execution time	Memory
1289979		lucaskojima	Cave (IOI13_cave)	C++17	100 / 100	230 ms	556 KiB

cave

#include "bits/stdc++.h"
#include "cave.h"
#define sz(x) (int)size(x)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)

using namespace std;
using ll = long long;
using pii = pair<int, int>;

const char nl = '\n';
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3f;
const int N   = 5000;

int d[N], s[N], q[N];

void exploreCave(int n) {
  vector<int> door_switch(n);

  for (int i = 0; i < n; i++) {

    for (int j = 0; j < n; j++)
      q[j] = 0;
    for (int j = 0; j < i; j++) {
      int id = door_switch[j];
      q[id] = s[id];
    }

    int pos = tryCombination(q);
    int t = ((pos == -1 || pos > i) ? 0 : 1);

    auto f = [&](auto f, int l, int r) -> int {
      if (l == r) return l;

      int m = (l + r) / 2;
      for (int j = 0; j < n; j++)
        q[j] = 1 - t;
      for (int j = l; j <= m; j++)
        q[j] = t;
      for (int j = 0; j < i; j++) {
        int id = door_switch[j];
        q[id] = s[id];
      }

      int ppos = tryCombination(q);
      if (ppos == -1 || ppos > i)
        return f(f, l, m);
      else
        return f(f, m + 1, r);
    };

    door_switch[i] = f(f, 0, n - 1);
    d[door_switch[i]] = i;
    s[door_switch[i]] = t;
  }

  answer(s, d);
}

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 24 / 24