Submission #303492

# Submission time Handle Problem Language Result Execution time Memory
303492 2020-09-20T11:09:04 Z rama_pang Counting Mushrooms (IOI20_mushrooms) C++14
100 / 100
19 ms 1408 KB
#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;

int count_mushrooms(int n) {
  const auto Solve = [&](int size_limit) {
    int ans = 1;

    set<int> unknown;
    for (int i = 1; i < n; i++) {
      unknown.emplace(i);
    }
    vector<int> A, B;
    A.emplace_back(0);

    while (!unknown.empty() && (int) max(A.size(), B.size()) < size_limit) {
      if (unknown.size() == 1 || max(A.size(), B.size()) == 1) {
        // query A?
        // can identify ?
        int u = *begin(unknown);
        unknown.erase(u);
        if (use_machine({0, u}) == 1) {
          B.emplace_back(u);
        } else {
          A.emplace_back(u);
          ans += 1;
        }
      } else if (unknown.size() < 5 || max(A.size(), B.size()) < 3 || min(A.size(), B.size()) < 2) {
        // query A?A?
        // can identify both ?
        bool swapped = A.size() < 2;
        if (swapped) {
          swap(A, B);
        }

        int u = *begin(unknown);
        unknown.erase(u);
        int v = *begin(unknown);
        unknown.erase(v);

        int q = use_machine({A[0], u, A[1], v});
        if (q == 0) {
          A.emplace_back(u);
          A.emplace_back(v);
          ans += swapped ? 0 : 2;
        } else if (q == 1) {
          A.emplace_back(u);
          B.emplace_back(v);
          ans += 1;
        } else if (q == 2) {
          B.emplace_back(u);
          A.emplace_back(v);
          ans += 1;
        } else if (q == 3) {
          B.emplace_back(u);
          B.emplace_back(v);
          ans += swapped ? 2 : 0;
        }
        if (swapped) {
          swap(A, B);
        }
      } else {
        // query A?A?A?
        // if first and second ? is the same, can uniquely identify them
        // otherwise, query B?BA?A?A?, where the first and second ? is the
        // same as previously, and other 2 is new element
        // can uniquely identify all of them
        int oldA = A.size();
        bool swapped = A.size() < B.size();
        if (swapped) {
          swap(A, B);
        }

        int u = *begin(unknown);
        unknown.erase(u);
        int v = *begin(unknown);
        unknown.erase(v);
        int w = *begin(unknown);
        unknown.erase(w);

        int q = use_machine({A[0], u, A[1], v, A[2], w});
        if (q & 1) {
          q--;
          B.emplace_back(w);
        } else {
          A.emplace_back(w);
        }
        if (q == 0) {
          A.emplace_back(u);
          A.emplace_back(v);
        } else if (q == 4) {
          B.emplace_back(u);
          B.emplace_back(v);
        } else {
          int c = *begin(unknown);
          unknown.erase(c);
          int d = *begin(unknown);
          unknown.erase(d); 
          q = use_machine({B[0], u, B[1], A[0], v, A[1], c, A[2], d}) - 1;
          if (q & 1) {
            B.emplace_back(d);
          } else {
            A.emplace_back(d);
          }
          if (q & 2) {
            B.emplace_back(c);
          } else {
            A.emplace_back(c);
          }
          if (q & 4) {
            A.emplace_back(u);
            B.emplace_back(v);
          } else {
            B.emplace_back(u);
            A.emplace_back(v);
          }
        }
        if (swapped) {
          swap(A, B);
        }
        ans += int(A.size()) - oldA;
      }
    }

    while (!unknown.empty()) {
      bool swapped = A.size() < B.size();
      if (swapped) {
        swap(A, B);
      }
      vector<int> que;
      for (auto i : A) {
        que.emplace_back(i);
        que.emplace_back(*begin(unknown));
        unknown.erase(begin(unknown));
        if (unknown.empty()) {
          break;
        }
      }
      int q = use_machine(que);
      ans += swapped ? ((q + 1) / 2) : (int(que.size()) / 2 - (q + 1) / 2);
      if (q & 1) {
        B.emplace_back(que.back());
      } else {
        A.emplace_back(que.back());
      }
      if (swapped) {
        swap(A, B);
      }
    }
    return ans;
  };
  
  return Solve(100);
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 1 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 3 ms 360 KB Output is correct
7 Correct 12 ms 1256 KB Output is correct
8 Correct 14 ms 1280 KB Output is correct
9 Correct 13 ms 1280 KB Output is correct
10 Correct 13 ms 1188 KB Output is correct
11 Correct 11 ms 1280 KB Output is correct
12 Correct 12 ms 1312 KB Output is correct
13 Correct 12 ms 1308 KB Output is correct
14 Correct 6 ms 848 KB Output is correct
15 Correct 14 ms 1324 KB Output is correct
16 Correct 14 ms 1304 KB Output is correct
17 Correct 6 ms 768 KB Output is correct
18 Correct 12 ms 1312 KB Output is correct
19 Correct 13 ms 1280 KB Output is correct
20 Correct 14 ms 1280 KB Output is correct
21 Correct 14 ms 1408 KB Output is correct
22 Correct 14 ms 1280 KB Output is correct
23 Correct 12 ms 1308 KB Output is correct
24 Correct 7 ms 848 KB Output is correct
25 Correct 13 ms 1320 KB Output is correct
26 Correct 14 ms 1280 KB Output is correct
27 Correct 14 ms 1280 KB Output is correct
28 Correct 13 ms 1312 KB Output is correct
29 Correct 13 ms 1312 KB Output is correct
30 Correct 12 ms 1312 KB Output is correct
31 Correct 13 ms 1304 KB Output is correct
32 Correct 13 ms 1280 KB Output is correct
33 Correct 12 ms 1308 KB Output is correct
34 Correct 13 ms 1280 KB Output is correct
35 Correct 12 ms 1280 KB Output is correct
36 Correct 13 ms 1280 KB Output is correct
37 Correct 12 ms 1280 KB Output is correct
38 Correct 13 ms 1280 KB Output is correct
39 Correct 14 ms 1280 KB Output is correct
40 Correct 13 ms 1280 KB Output is correct
41 Correct 14 ms 1280 KB Output is correct
42 Correct 17 ms 1280 KB Output is correct
43 Correct 11 ms 1280 KB Output is correct
44 Correct 16 ms 1308 KB Output is correct
45 Correct 12 ms 1280 KB Output is correct
46 Correct 13 ms 1400 KB Output is correct
47 Correct 10 ms 1312 KB Output is correct
48 Correct 14 ms 1316 KB Output is correct
49 Correct 12 ms 1280 KB Output is correct
50 Correct 12 ms 1280 KB Output is correct
51 Correct 17 ms 1280 KB Output is correct
52 Correct 17 ms 1280 KB Output is correct
53 Correct 13 ms 1280 KB Output is correct
54 Correct 13 ms 1280 KB Output is correct
55 Correct 10 ms 1316 KB Output is correct
56 Correct 18 ms 1280 KB Output is correct
57 Correct 19 ms 1280 KB Output is correct
58 Correct 10 ms 1312 KB Output is correct
59 Correct 12 ms 1280 KB Output is correct
60 Correct 14 ms 1280 KB Output is correct
61 Correct 12 ms 1280 KB Output is correct
62 Correct 0 ms 256 KB Output is correct
63 Correct 1 ms 256 KB Output is correct
64 Correct 1 ms 256 KB Output is correct
65 Correct 1 ms 256 KB Output is correct
66 Correct 0 ms 256 KB Output is correct
67 Correct 0 ms 256 KB Output is correct
68 Correct 0 ms 256 KB Output is correct
69 Correct 0 ms 256 KB Output is correct
70 Correct 0 ms 256 KB Output is correct
71 Correct 0 ms 256 KB Output is correct
72 Correct 1 ms 256 KB Output is correct
73 Correct 0 ms 256 KB Output is correct
74 Correct 0 ms 256 KB Output is correct
75 Correct 1 ms 256 KB Output is correct
76 Correct 0 ms 256 KB Output is correct
77 Correct 0 ms 256 KB Output is correct
78 Correct 0 ms 256 KB Output is correct
79 Correct 0 ms 256 KB Output is correct
80 Correct 1 ms 256 KB Output is correct
81 Correct 1 ms 256 KB Output is correct
82 Correct 0 ms 256 KB Output is correct
83 Correct 0 ms 256 KB Output is correct
84 Correct 0 ms 256 KB Output is correct
85 Correct 0 ms 256 KB Output is correct
86 Correct 0 ms 256 KB Output is correct
87 Correct 0 ms 256 KB Output is correct
88 Correct 1 ms 256 KB Output is correct
89 Correct 0 ms 256 KB Output is correct
90 Correct 0 ms 256 KB Output is correct
91 Correct 1 ms 256 KB Output is correct