Submission #957891

#	Time	Username	Problem	Language	Result	Execution time	Memory
957891		BhavayGoyal	Snake Escaping (JOI18_snake_escaping)	C++14	0 / 100	1 ms	2396 KiB

snake_escaping

#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<class T> using oset = 
            tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define ll long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define endl "\n"

const int MOD = 1e9+7;
const int inf = 1e9;
const ll linf = 1e18;

const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());


// -------------------------------------------------- Main Code --------------------------------------------------

const int N = (1<<20)+5;
int n, q, arr[N], dp[N];
map<string, int> mp;

int getAns(string &s) {
    int num = 0;
    for (int i = 0; i < n; i++) {
        if (s[i] == '?') {num = -1; break;}
        else num += (1<<(n-i-1))*(s[i]-'0');
    }
    if (num != -1) {
        return arr[num];
    }

    int ans = 0;
    for (int i = 0; i < n; i++) {
        if (s[i] == '?') {
            s[i] = '1';
            ans += getAns(s);
            s[i] = '0';
            ans += getAns(s);
            s[i] = '?';
            break;
        }
    }

    return ans;
}

void sol() {
    cin >> n >> q;
    for (int i = 0; i < (1<<n); i++) {char x; cin >> x; arr[i] = x-'0';}

    // for (int mask = 0; mask < (1<<n); mask++) {
    //     dp[mask] = arr[mask];
    //     for (int i = 0; i < n; i++) {
    //         if (mask&(1<<i)) {
    //             dp[mask] = dp[mask] + dp[mask^(1<<i)];
    //         }
    //     }
    // }
    for(int i = 0; i<(1<<n); ++i)
        dp[i] = arr[i];
    for(int i = 0;i < n; ++i) for(int mask = 0; mask < (1<<n); ++mask){
        if(mask & (1<<i))
            dp[mask] += dp[mask^(1<<i)];
    }

    while (q--) {
        string s; cin >> s;
        if (mp.find(s) != mp.end()) {cout << mp[s] << endl; return;}

        int ans = 0;
        // int one = 0, zero = 0, question = 0;
        // for (int i = 0; i < n; i++) {
        //     one += s[i]=='1';
        //     zero += s[i]=='0';
        //     question += s[i]=='?';
        // }

        // if (one <= 20) {
        //     vi temp;
        //     int num = 0;
        //     reverse(all(s));
        //     for (int i = 0; i < n; i++) {
        //         if (s[i] == '1') temp.pb(i);
        //         if (s[i] == '1' || s[i] == '?') num += (1<<i);
        //     }

        //     for (int i = 0; i < (1<<temp.size()); i++) {
        //         int tempNum = num, ct = 0;
        //         for (int j = 0; j < temp.size(); j++) {
        //             if (i&(1<<j)) {
        //                 tempNum ^= (1<<temp[j]);
        //                 ct++;
        //             }
        //         }
        //         if (ct%2 != 0) ans -= dp[tempNum];
        //         else ans += dp[tempNum];
        //     }
        // }
        // else if (question <= 6) {
            ans = getAns(s);
        // }
        // else {

        // }

        cout << (mp[s] = ans) << endl;
    }
}

int main () {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t = 1;
    // cin >> t; 
    while (t--) {
        sol();
    }
    return 0;
}

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