Submission #957930

#	Time	Username	Problem	Language	Result	Execution time	Memory
957930		BhavayGoyal	Snake Escaping (JOI18_snake_escaping)	C++14	0 / 100	25 ms	65536 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[21][N], dp2[21][N];

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;
}

int subSum(int idx, int mask) {
    if (idx < 0) return arr[mask];
    if (dp[idx][mask] != -1) return dp[idx][mask];
    int ans = subSum(idx-1, mask);
    if (mask&(1<<idx)) ans = (ans + subSum(idx-1, mask^(1<<idx)));
    return dp[idx][mask] = ans;
}

int subSum2(int idx, int mask) {
    if (idx < 0) return arr[mask];
    if (dp2[idx][mask] != -1) return dp2[idx][mask];
    int ans = subSum2(idx-1, mask);
    if ((mask&(1<<idx)) == 0) ans = (ans + subSum2(idx-1, mask^(1<<idx)));
    return dp2[idx][mask] = ans;
}

void sol() {
    memset(dp, -1, sizeof dp);
    memset(dp2, -1, sizeof dp);
    cin >> n >> q;
    for (int i = 0; i < (1<<n); i++) {char x; cin >> x; arr[i] = x-'0';}

    while (q--) {
        string s; cin >> s;
        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 (zero <= 6) {
            vi temp;
            int num = 0;
            reverse(all(s));
            for (int i = 0; i < n; i++) {
                if (s[i] == '0') temp.pb(i);
                if (s[i] == '1') num += (1<<i);
            }

            int ans = 0;
            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)) == 0) {
                        tempNum ^= (1<<temp[j]);
                        ct++;
                    }
                }
                if (ct%2 != 0) ans -= subSum2(n-1, tempNum);
                else ans += subSum2(n-1, tempNum);
            }

            cout << ans << endl;
        }
        else if (one <= 6) {
            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);
            }

            int ans = 0;
            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 -= subSum(n-1, tempNum);
                else ans += subSum(n-1, tempNum);
            }

            cout << ans << endl;
        }
        else {
            cout << getAns(s) << endl;
        }
    }
}

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

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

Compilation message (stderr)

snake_escaping.cpp: In function 'void sol()':
snake_escaping.cpp:106:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |                 for (int j = 0; j < temp.size(); j++) {
      |                                 ~~^~~~~~~~~~~~~
snake_escaping.cpp:130:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  130 |                 for (int j = 0; j < temp.size(); j++) {
      |                                 ~~^~~~~~~~~~~~~

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