Submission #722982

#	Time	Username	Problem	Language	Result	Execution time	Memory
722982		drdilyor	Stranded Far From Home (BOI22_island)	C++17	10 / 100	1092 ms	15516 KiB

island

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

int main() {
    int n, m;
    cin >> n >> m;
    vector s(n, 0);
    for (int& i : s) cin >> i;

    vector<int> ix(n);
    for (int i{}; i < n ;i++) ix[i] = i;
    stable_sort(ix.begin(), ix.end(), [&](int a, int b) {
        return s[a] > s[b];
    });
    vector<int> jx(n);
    for (int i = 0; i < n; i ++)
        jx[ix[i]] = i;
    stable_sort(s.begin(), s.end(), greater{});

    vector<vector<int>> adj(n);
    for (int i = 0; i < m ;i++) {
        int u, v;
        cin >> u >> v;
        u--;v--;
        adj[jx[u]].push_back(jx[v]);
        adj[jx[v]].push_back(jx[u]);
    }

    //for (int i : ix) cout << i << ' ';cout << endl;
    //for (int i : jx) cout << i << ' ';cout << endl;
    //for (int i : s) cout << i << ' ';cout << endl;
    string res(n, '?');
    vector<int> back(n, -1);
    for (int i =n -1; i >= 0;i --) {
        set<pair<int,int>> st;
        vector vis(n, 0);
        st.emplace(0, i);
        vis[i] = 1;
        ll sum = s[i];
        while (st.size()) {
            auto [w, j] = *st.begin();
            if (sum < w) break;
            if (j < i) {
                back[i] = j;
                break;
            }
            st.erase(st.begin());
            sum += w;
            for (int e : adj[j]) {
                if (!vis[e]) {
                    vis[e] = 1;
                    st.emplace(s[e], e);
                }
            }
        }
        if (back[i] == -1)
            res[i] = char('0' + st.empty());
    }
    string ans(n, '?');
    assert(res[0] == '1');
    for (int i = 1; i < n;i++) {
        if (back[i] != -1) res[i] = res[back[i]];
    }
    for (int i = 0; i < n; i++) {
        ans[ix[i]] = res[i];
    }
    cout << ans << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 30
• Subtask 5: 0 / 35