Submission #619721

#	Time	Username	Problem	Language	Result	Execution time	Memory
619721		Do_you_copy	Snake Escaping (JOI18_snake_escaping)	C++17	22 / 100	2075 ms	17992 KiB

snake_escaping

#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define taskname "test"
#define fi first
#define se second
#define pb push_back
#define faster ios_base::sync_with_stdio(0); cin.tie(0);
using namespace std;
using ll = long long;
using ull = unsigned ll;
using ld = long double;
using pii = pair <int, int>;
using pil = pair <int, ll>;
using pli = pair <ll, int>;
using pll = pair <ll, ll>;
mt19937 Rand(chrono::steady_clock::now().time_since_epoch().count());

ll min(const ll &a, const ll &b){
    return (a < b) ? a : b;
}

ll max(const ll &a, const ll &b){
    return (a > b) ? a : b;
}

//const ll Mod = 1000000007;
//const ll Mod2 = 999999999989;
//only use when required
const int maxN = 20;

int n, q;
string s, t;
int dp[(1 << maxN) + 2];
int f[(1 << maxN) + 2];
int cnt[(1 << maxN) + 2];

void WriteInt(int x)
{
    if (x > 9)
        WriteInt(x / 10);
    putchar(x % 10 + '0');
}

inline int inv(int i){
    return ((1 << n) - 1) ^ i;
}
void Init(){
    cin >> n >> q >> s;
    for (int i = 0; i < int(s.length()); ++i){
        dp[i] = s[i] - '0';
        f[inv(i)] = dp[i];
    }
    for (int i = 0; i < n; ++i){
        for (int j = 1; j < 1 << n; ++j){
            if (j & (1 << i)){
                dp[j] += dp[j ^ (1 << i)];
            }
        }
    }
    for (int i = 0; i < n; ++i){
        for (int j = 0; j < 1 << n; ++j){
            if (j & (1 << i)){
                f[j] += f[j ^ (1 << i)];
            }
        }
    }
    for (int i = 1; i < 1 << n; ++i){
        int j = i & -i;
        cnt[i] = cnt[i ^ j] + 1;
    }
    while (q--){
        cin >> t;
        vector <int> A, B, C;
        vector <int> val((1 << n) + 1, 0);
        for (int i = 0; i < int(t.length()); ++i){
            if (t[i] == '0') A.pb(n - i - 1);
            if (t[i] == '1') B.pb(n - i - 1);
            if (t[i] == '?') C.pb(n - i - 1);
        }
        int x = A.size(), y = B.size(), z = C.size();
        if (x <= 6){
            int tem = 0, ans = 0;
            for (const int &i: C) tem += 1 << i;
            for (int i = 0; i < 1 << x; ++i){
                int t = i & -i;
                if (i != 0)
                val[i] = val[i ^ t] + (1 << A[__lg(t)]);
                if ((x & 1) ^ (cnt[i] & 1)) ans -= f[val[i] + tem];
                else ans += f[val[i] + tem];
            }
            WriteInt(ans);
            putchar('\n');
        }
        else if (y <= 6){
            int tem = 0, ans = 0;
            for (int i: C) tem += 1 << i;
            for (int i = 0; i < 1 << y; ++i){
                int t = i & -i;
                if (i != 0)
                val[i] = val[i ^ t] + (1 << B[__lg(t)]);
                if ((y & 1) ^ (cnt[i] & 1)) ans -= dp[val[i] + tem];
                else ans += dp[val[i] + tem];
            }
            WriteInt(ans);
            putchar('\n');
        }
        else{
            //brute all ?s
            for (int i = 1; i < 1 << z; ++i){
                int t = i & -i;
                val[i] = val[i ^ t] + (1 << C[__lg(t)]);
            }
            int tem = 0, ans = 0;
            for (const auto i: B) tem += 1 << i;
            for (int i = 0; i < 1 << z; ++i){
                ans += s[val[i] + tem] - '0';
            }
            WriteInt(ans);
            putchar('\n');
        }
    }
}


int main(){
    if (fopen(taskname".inp", "r")){
        freopen(taskname".inp", "r", stdin);
        //freopen(taskname".out", "w", stdout);
    }
    faster;
    ll tt = 1;
    //cin >> tt;
    while (tt--){
        Init();
    }
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:128:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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