Submission #1175464

#	Time	Username	Problem	Language	Result	Execution time	Memory
1175464		TrendBattles	Snake Escaping (JOI18_snake_escaping)	C++17	75 / 100	268 ms	15116 KiB

snake_escaping

#include <bits/stdc++.h>
using namespace std;
using lli = long long int;

#define INFILE "main.inp"
#define OUTFILE "main.out"


namespace SUBTASK_small_L {
    void main(int L, int Q, string digits) {
        vector <int> pow_3(L + 1);
        pow_3[0] = 1;
        for (int i = 1; i <= L; ++i) {
            pow_3[i] = pow_3[i - 1] * 3;
        }

        const int M = pow_3[L];
        vector <int> mask_3(1 << L);
        vector <int> finale(M);

        for (int m = 1; m < (1 << L); ++m) {
            int p = m & -m;

            mask_3[m] = mask_3[m ^ p] + pow_3[__builtin_ctz(p)];
        }

        for (int m = 0; m < (1 << L); ++m) {
            int x = digits[m] - '0';

            for (int p = 0; p < (1 << L); ++p) {
                int f_m = mask_3[p] * 2 + mask_3[m & ~p];

                finale[f_m] += x;
            }
        }

        for (int _ = 0; _ < Q; ++_) {
            string que; cin >> que;
            int m = 0;
            for (int i = 0; i < L; ++i) {
                if (que[i] == '1') m += pow_3[L - i - 1];
                else if (que[i] == '?') m += pow_3[L - i - 1] * 2;
            }
            cout << finale[m] << '\n';
        }
    }
}

namespace SUBTASK_small_Q {
    const int HIGH_BIT = 20, MAX_MASK = 1 << HIGH_BIT;
    int sum_A[MAX_MASK], sum_B[MAX_MASK];
    int bit_cnt[MAX_MASK];
    void main(int L, int Q, string digits) {
        for (int m = 0; m < (1 << L); ++m) {
            sum_A[m] = digits[m] - '0';
            sum_B[~(-1 << L) ^ m] = sum_A[m];

            bit_cnt[m] = bit_cnt[m >> 1] ^ (m & 1);
        }
        
        for (int b = 0; b < L; ++b) {
            for (int m = 0; m < (1 << L); ++m) {
                if ((m >> b & 1) == 0) {
                    sum_A[m] += sum_A[m ^ (1 << b)];
                    sum_B[m] += sum_B[m ^ (1 << b)];
                }
            }
        }

        for (int _ = 0; _ < Q; ++_) {
            string que; cin >> que;
            int ans = 0;
            if (count(que.begin(), que.end(), '0') <= L / 2) {
                int allowed = 0, banned = 0;
                for (int i = 0; i < L; ++i) {
                    if (que[i] == '1') allowed ^= 1 << (L - i - 1);
                    if (que[i] == '0') banned ^= 1 << (L - i - 1);
                }

                for (int p = banned; p >= 0; p = (p - 1) & banned) {
                    if (bit_cnt[p]) {
                        ans -= sum_A[allowed ^ p];
                    } else {
                        ans += sum_A[allowed ^ p];
                    }

                    if (p == 0) break;
                }
            } else {
                int allowed = 0, banned = 0;
                for (int i = 0; i < L; ++i) {
                    if (que[i] == '0') allowed ^= 1 << (L - i - 1);
                    if (que[i] == '1') banned ^= 1 << (L - i - 1);
                }

                for (int p = banned; p >= 0; p = (p - 1) & banned) {
                    if (bit_cnt[p]) {
                        ans -= sum_B[allowed ^ p];
                    } else {
                        ans += sum_B[allowed ^ p];
                    }

                    if (p == 0) break;
                }
            }
            cout << ans << '\n';
        }
    }
}
int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    if (fopen(INFILE, "r")) {
        freopen(INFILE, "r", stdin);
        freopen(OUTFILE, "w", stdout);
    }

    int L, Q; cin >> L >> Q;
    string digits; cin >> digits;

    if (L <= 13) {
        SUBTASK_small_L::main(L, Q, digits);
        return 0;
    }
    if (Q <= 50'000) {
        SUBTASK_small_Q::main(L, Q, digits);
        return 0;
    }
    return 0;
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:113:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |         freopen(INFILE, "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
snake_escaping.cpp:114:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  114 |         freopen(OUTFILE, "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 10 / 10
• Subtask 4: 53 / 53
• Subtask 5: 0 / 25