Submission #1304061

#	Time	Username	Problem	Language	Result	Execution time	Memory
1304061		anhkiet	Snake Escaping (JOI18_snake_escaping)	C++20	0 / 100	19 ms	31700 KiB

snake_escaping

#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 100;
#define int long long
#define fi first
#define pdi pair < pair < double, double >, int >
#define se second
#define ll long long
#define pii pair < int, int >
const int MOD = 1e9 + 7;
const ll inf = 1e18;

string s;
int l, q;
int n, ans;
char b[maxn];
int c[maxn];
string qry[maxn];

void xuly() {
    for (int i = 1; i <= l; i++) {
        if (c[i] != (b[i] - '0') && b[i] != '?') return;
    }

    int cur = 0;
    int t = 0;
    for (int i = l; i >= 1; i--) {
        if (c[i] == 1) t += (1 << cur);
        cur ++;
    }

//    for (int i = 1; i <= l; i++) cout << c[i];
//    cout << "  " << t;
//    cout << endl;

    ans += (s[t] - '0');
}

void backtrack(int i) {
    for (int j = 0; j <= 1; j++) {
        c[i] = j;
        if (i == l) xuly();
        else backtrack(i + 1);
    }
}

namespace subtask1 {
    void solve() {
    for (int i = 1; i <= q; i++) {
        for (int j = 1; j <= l; j++) {
               b[j] = qry[i][j - 1];
        }
            backtrack(1);
            cout << ans << '\n';
            ans = 0;
        }
    }
}

namespace subtaskbip {
    vector < int > bit0, bit1, bitH;
    int dp[2][(1 << 20) + 5], base[(1 << 20) + 5];

    void solve() {
        int S = (1 << l);
        int matna = 0;
        for (int matna = 0; matna < S; matna++) {
            dp[1][matna] = (s[matna] - '0');
            base[matna] = (s[matna] - '0');
            int nmatna = (~matna) & ((1 << l)- 1);
            dp[0][nmatna] = base[matna];
        }

        for (int i = 0; i < l; i++) {
            for (int mask = 0; mask < S; mask++) {
                    if (mask >> i & 1) {
                        int nmask = mask ^ (1 << i);
                        dp[1][mask] += dp[1][nmask];
                    }
                }
            }

        for (int i = 0; i < l; i++) {
            for (int mask = 0; mask < S; mask++) {
                    if (!(mask >> i & 1)) {
                        int nmask = mask | (1 << i);
                        dp[0][mask] += dp[0][nmask];
                    }
                }
            }

        for (int i= 1; i <= q; i++) {
            string st = qry[i];
            bit1.clear();
            bit0.clear();
            bitH.clear();
            reverse(st.begin(), st.end());
            for (int j = 0; j < st.size(); j++) {
                char x = st[j];
                if (x == '0') bit0.push_back(j);
                if (x == '1') bit1.push_back(j);
                if (x == '?') bitH.push_back(j);
            }

            int ans = 0;

             int f = 0;
                for (int i = 0; i < st.size(); i++) {
                    if (st[i] == '1') f |= (1 << i);
                }

            if (bitH.size() <= 6) {

                int LIM = (1 << (int)bitH.size());
                for (int mask = 0; mask < LIM; mask++) {
                    int cur = f;
                    for (int i = 0; i < bitH.size(); i++) {
                        if (mask >> i & 1) {
                            int bit = bitH[i];
                            cur |= (1 << bit);
                        }
                    }
                    ans += base[cur];
                }
                cout << ans << '\n';
            } else if (bit1.size() <= 6) {
                int LIM = (1 << (int)bit1.size());
                for (int mask = 0; mask < LIM; mask++) {
                    int cur = f;
                    for (int i = 0; i < bit1.size(); i++) {
                        if (mask >> i & 1) {
                            int bit = bit1[i];
                            cur ^= (1 << bit);
                        }
                    }
                    if (__builtin_popcount(mask) % 2) ans -= dp[1][cur];
                    else ans += dp[1][cur];
                }

                cout << ans << '\n';
            } else if (bit0.size() <= 6) {
                f = 0;
                for (int i = 0; i < st.size(); i++) {
                    if (st[i] != '1') f |= (1 << i);
                }
                int LIM = (1 << (int)bit0.size());
                for (int mask = 0; mask < LIM; mask++) {
                    int cur = f;
                    for (int i = 0; i < bit0.size(); i++) {
                        if (mask >> i & 1) {
                            int bit = bit0[i];
                            cur ^= (1 << bit);
                        }
                    }
                    if (__builtin_popcount(mask) % 2) ans -= dp[0][cur];
                    else ans += dp[0][cur];
                }

                cout << ans << '\n';
            }
        }
    }
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);     cout.tie(0);

    #define NAME "test"
    if (fopen(NAME".INP", "r")) {
        freopen(NAME".INP", "r",stdin);
        freopen(NAME".OUT", "w",stdout);
    }

    cin >> l >> q;
    cin >> s;

    for (int i = 1; i <= q; i++) {
        cin >> qry[i];
    }

 
   subtaskbip::solve();
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:171:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  171 |         freopen(NAME".INP", "r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
snake_escaping.cpp:172:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  172 |         freopen(NAME".OUT", "w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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