Submission #250816

#	Time	Username	Problem	Language	Result	Execution time	Memory
250816		NONAME	Ili (COI17_ili)	C++14	100 / 100	2892 ms	24400 KiB

ili

#include <bits/stdc++.h>
#define dbg(x) cerr << #x << " = " << x << "\n"
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie()
using namespace std;
using ll = long long;

const int N = int(2e4) + 500;

int n, m;
array <int, 2> a[N];
vector <int> g[N];
bool mk[N], m0[N], m1[N];
string s;
bitset <N> n1, vis[N];

void dfs(int v) {
    if (mk[v])
        return;
    mk[v] = 1;
    if (v <= n)
        return;
    dfs(a[v][0]);
    dfs(a[v][1]);
}

int input() {
    string t;
    cin >> t;
    int len = int(t.size()), res = 0;
    for (int i = 1; i < len; ++i)
        (res *= 10) += (t[i] - '0');

    if (t[0] == 'c')
        return res + n;
    return res;
}

int main() {
    fast_io;

    cin >> n >> m;
    cin >> s;
    s = "*" + s;
    for (int i = n + 1; i <= n + m; ++i) {
        a[i] = {input(), input()};

        g[a[i][0]].push_back(i);
        g[a[i][1]].push_back(i);
    }

    for (int i = n + 1; i <= n + m; ++i)
        if (s[i - n] == '0')
            dfs(i);

    for (int i = 1; i <= n; ++i)
        if (!mk[i]) n1[i] = 1;

    for (int i = 1; i <= m; ++i) {
        for (int j = 1; j <= n + m; ++j)
            mk[j] = 0;

        if (s[i] != '?') {
            if (s[i] == '1') m1[i] = 1;
                else m0[i] = 1;
            continue;
        }

        dfs(i + n);
        for (int j = 1; j <= n; ++j)
            if (mk[j])
                vis[i][j] = 1;

        if ((vis[i] & n1).none()) m0[i] = 1;
            else m1[i] = 1;
    }

    for (int i = 1; i <= m; ++i) {
        if (s[i] == '?' && !m0[i]) {
            m0[i] = 1;

            for (int j = 1; j <= n + m; ++j)
                mk[j] = 0;

            queue <int> q;
            for (int j = 1; j <= n; ++j)
                if (n1[j] && !vis[i][j])
                    q.push(j);

            while (!q.empty()) {
                int v = q.front();
                q.pop();
                for (auto u : g[v])
                    if (!mk[u]) {
                        mk[u] = 1;
                        q.push(u);
                    }
            }

            for (int j = 1; j <= m; ++j)
                if (s[j] == '1' && !mk[j + n])
                    m0[i] = 0;
        }

        if (m0[i] && m1[i]) cout << "?"; else
        if (m0[i]) cout << "0";
            else cout << "1";
    }
}

• Subtask 1: 7 / 7
• Subtask 2: 42 / 42
• Subtask 3: 51 / 51