Submission #723078

#	Time	Username	Problem	Language	Result	Execution time	Memory
723078		dxz05	Stranded Far From Home (BOI22_island)	C++17	40 / 100	1084 ms	110756 KiB

island

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define all(x) (x).begin(), (x).end()
#define MP make_pair
const int N = 200500;

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

int s[N];
vector<int> g[N];
bool can[N];

vector<int> comp;
int color[N];

void dfs(int v){
    color[v] = 2;
    comp.push_back(v);
    for (int u : g[v]){
        if (!can[u] && color[u] == 1){
            dfs(u);
        }
    }
}

void go(vector<int> &vertices, long long need){
    long long sum = 0;
    int mx = 0;
    for (int v : vertices){
        sum += s[v];
        mx = max(mx, s[v]);
        color[v] = 1;
    }

    if (sum < need) return;

    for (int v : vertices){
        if (s[v] == mx) can[v] = true;
    }

    vector<vector<int>> components;
    for (int v : vertices){
        if (color[v] == 1 && !can[v]){
            comp.clear();
            dfs(v);
            components.push_back(comp);
        }
    }

    for (auto vec : components){
        go(vec, mx);
    }
}

void solve(){
    int n, m;
    cin >> n >> m;

    for (int i = 0; i < n; i++){
        cin >> s[i];
    }

    while (m--){
        int u, v;
        cin >> u >> v;
        --u, --v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    ll total = accumulate(s, s + n, 0ll);

    vector<int> vertices(n);
    iota(all(vertices), 0);

    go(vertices, total);

    for (int i = 0; i < n; i++){
        cout << can[i];
    }

}

int main() {
    ios_base::sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    solve();

    return 0;
}

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