Submission #303623

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
303623	2020-09-20T13:33:27 Z	alex_velea	Counting Mushrooms (IOI20_mushrooms)	C++17	10 / 100	1735 ms	416 KB

mushrooms

#include <bitset>
#include <array>
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

#define DEBUG if(0)

int count_mushrooms(int n);

int use_machine(vector<int> x);

const int kMaxLen = 8;

struct Solver {
    int start, n;
    bool valid[1 << kMaxLen];

    Solver(int start, int n) : start(start), n(n) {
        for (int i = 0; i < (1 << n); i += 1) {
            valid[i] = true;
        }
    }

    void FixFirst() {
        int firstEl = use_machine({0, start});
        for (int i = 0; i < (1 << n); i += 1) {
            valid[i] = (i & 1) == firstEl;
        }
    }
    
    int GetCount(int mask) {
        int ans = 0;
        for (int i = 0; i < n; i += 1) {
            cerr << (!!(mask & (1 << i)));
            ans += (mask & (1 << i)) == 0;
        }
        return ans;
    }

    int GetCost(int state, vector<int> order) {
        int cost = 0;
        for (int i = 1; i < (int)order.size(); i += 1) {
            cost += (!!(state & (1 << order[i - 1]))) != (!!(state & (1 << order[i]))); 
        }
        return cost;
    }

    vector<int> GetBestMove() {
        vector<int> best;
        int best_cost = (1 << n);
        vector<int> current_order = {};
        for (int i = 0; i < n; i += 1) {
            current_order.push_back(i);
        }

        for (int i = 0; i < (50); i += 1) {
            random_shuffle(current_order.begin(), current_order.end());
            
            array<int, kMaxLen> freq;
            for (int i = 0; i < kMaxLen; i += 1) {
                freq[i] = 0;
            }

            for (int i = 0; i < (1 << n); i += 1) {
                if (valid[i]) {
                    int cost = GetCost(i, current_order);
                    DEBUG cerr << cost << ' ';
                    freq[cost] += 1;
                }
            }

            int mx = 0;
            for (auto& itr : freq) {
                mx = max(mx, itr);
            }

            DEBUG cerr << "Current max = " << mx << '\n';

            if (best_cost > mx) {
                mx = best_cost;
                best = current_order;
            }
        }
        return best;
    }

    int Solve() {
        DEBUG cerr << "Solve .. " << start << '\t' << n << '\n';
        FixFirst();
        vector<int> available;
        while (1) {
            DEBUG cerr << "Run .. \n";
            available.clear();
            for (int i = 0; i < (1 << n); i += 1) {
                if (valid[i]) {
                    bitset<kMaxLen> b(i);
                    DEBUG cerr << "Ok .. " << b << "\n";
                    available.push_back(i);
                }
            }

            if (available.size() == 1) {
                return GetCount(available[0]); 
            }

            auto best = GetBestMove();
            DEBUG {
                cerr << "Best = \t";
                for (auto& itr : best) {
                    cerr << itr << '\t';
                }
                cerr << '\n';
            }
            auto q = best;
            for (auto& itr : q) {
                itr += start;
            }

            int ans = use_machine(q);
            DEBUG cerr << "Ans = " << ans << '\n';
            for (int i = 0; i < (1 << n); i += 1) {
                if (valid[i] and GetCost(i, best) != ans) {
                    valid[i] = false;
                }
            }
        }
    }
};

int count_mushrooms(int n) {
    int ans = 1;
    for (int i = 1; i < n; i += kMaxLen) {
        Solver s(i, min(kMaxLen, n - i));
        ans += s.Solve();
    }
    DEBUG cerr << "ans = " << ans << '\n';
    cerr << '\n';
    return ans;
}

Subtask #1

10.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	256 KB	Output is correct
2	Correct	0 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	14 ms	256 KB	Output is correct
6	Partially correct	145 ms	256 KB	Output is partially correct
7	Partially correct	888 ms	388 KB	Output is partially correct
8	Partially correct	1000 ms	392 KB	Output is partially correct
9	Partially correct	1166 ms	388 KB	Output is partially correct
10	Partially correct	1402 ms	392 KB	Output is partially correct
11	Partially correct	1446 ms	388 KB	Output is partially correct
12	Partially correct	1459 ms	388 KB	Output is partially correct
13	Partially correct	1163 ms	388 KB	Output is partially correct
14	Partially correct	738 ms	380 KB	Output is partially correct
15	Partially correct	1570 ms	396 KB	Output is partially correct
16	Partially correct	1735 ms	392 KB	Output is partially correct
17	Partially correct	681 ms	380 KB	Output is partially correct
18	Partially correct	1180 ms	392 KB	Output is partially correct
19	Partially correct	1502 ms	392 KB	Output is partially correct
20	Partially correct	1504 ms	380 KB	Output is partially correct
21	Partially correct	1515 ms	392 KB	Output is partially correct
22	Partially correct	1499 ms	384 KB	Output is partially correct
23	Partially correct	1434 ms	388 KB	Output is partially correct
24	Partially correct	745 ms	380 KB	Output is partially correct
25	Partially correct	1622 ms	396 KB	Output is partially correct
26	Partially correct	1717 ms	396 KB	Output is partially correct
27	Partially correct	1490 ms	380 KB	Output is partially correct
28	Partially correct	1484 ms	396 KB	Output is partially correct
29	Partially correct	1454 ms	396 KB	Output is partially correct
30	Partially correct	1429 ms	392 KB	Output is partially correct
31	Partially correct	1437 ms	396 KB	Output is partially correct
32	Partially correct	1527 ms	392 KB	Output is partially correct
33	Partially correct	1590 ms	392 KB	Output is partially correct
34	Partially correct	1605 ms	400 KB	Output is partially correct
35	Partially correct	1502 ms	392 KB	Output is partially correct
36	Partially correct	1555 ms	392 KB	Output is partially correct
37	Partially correct	1398 ms	392 KB	Output is partially correct
38	Partially correct	1520 ms	392 KB	Output is partially correct
39	Partially correct	1523 ms	392 KB	Output is partially correct
40	Partially correct	1490 ms	396 KB	Output is partially correct
41	Partially correct	1600 ms	400 KB	Output is partially correct
42	Partially correct	1454 ms	392 KB	Output is partially correct
43	Partially correct	1447 ms	400 KB	Output is partially correct
44	Partially correct	1560 ms	392 KB	Output is partially correct
45	Partially correct	1459 ms	388 KB	Output is partially correct
46	Partially correct	1551 ms	388 KB	Output is partially correct
47	Partially correct	1569 ms	392 KB	Output is partially correct
48	Partially correct	1436 ms	396 KB	Output is partially correct
49	Partially correct	1465 ms	400 KB	Output is partially correct
50	Partially correct	1492 ms	388 KB	Output is partially correct
51	Partially correct	1454 ms	392 KB	Output is partially correct
52	Partially correct	1484 ms	392 KB	Output is partially correct
53	Partially correct	1615 ms	400 KB	Output is partially correct
54	Partially correct	1434 ms	388 KB	Output is partially correct
55	Partially correct	1444 ms	392 KB	Output is partially correct
56	Partially correct	1529 ms	392 KB	Output is partially correct
57	Partially correct	1435 ms	396 KB	Output is partially correct
58	Partially correct	1458 ms	392 KB	Output is partially correct
59	Partially correct	1615 ms	400 KB	Output is partially correct
60	Partially correct	1233 ms	392 KB	Output is partially correct
61	Partially correct	1165 ms	384 KB	Output is partially correct
62	Correct	1 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	1 ms	256 KB	Output is correct
67	Correct	1 ms	360 KB	Output is correct
68	Correct	1 ms	256 KB	Output is correct
69	Correct	1 ms	380 KB	Output is correct
70	Correct	1 ms	256 KB	Output is correct
71	Correct	1 ms	256 KB	Output is correct
72	Correct	1 ms	256 KB	Output is correct
73	Correct	1 ms	256 KB	Output is correct
74	Correct	1 ms	256 KB	Output is correct
75	Correct	1 ms	384 KB	Output is correct
76	Correct	1 ms	256 KB	Output is correct
77	Correct	1 ms	256 KB	Output is correct
78	Correct	1 ms	256 KB	Output is correct
79	Correct	1 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	1 ms	256 KB	Output is correct
83	Correct	1 ms	416 KB	Output is correct
84	Correct	1 ms	256 KB	Output is correct
85	Correct	1 ms	384 KB	Output is correct
86	Correct	1 ms	384 KB	Output is correct
87	Correct	1 ms	256 KB	Output is correct
88	Correct	1 ms	256 KB	Output is correct
89	Correct	1 ms	256 KB	Output is correct
90	Correct	1 ms	256 KB	Output is correct
91	Correct	1 ms	256 KB	Output is correct