Submission #1217808

#	Time	Username	Problem	Language	Result	Execution time	Memory
1217808		Ghulam_Junaid	Stranded Far From Home (BOI22_island)	C++20	100 / 100	263 ms	38820 KiB

island

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

typedef long long ll;

const int N = 2e5 + 10;
int n, m, a[N], par[N];
ll sm[N];
vector<int> g[N], vals;
vector<pair<int, pair<int, int>>> edges;
set<int> alive[N];

int root(int v){
    return (par[v] == -1 ? v : par[v] = root(par[v]));
}

void merge(int u, int v, int w){
    if ((u = root(u)) == (v = root(v)))
        return ;

    if (sm[u] < w)
        alive[u].clear();
    if (sm[v] < w)
        alive[v].clear();

    if (alive[u].size() > alive[v].size())
        swap(u, v);
    par[u] = v;
    sm[v] += sm[u];
    for (int x : alive[u])
        alive[v].insert(x);
    alive[u].clear();
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    cin >> n >> m;
    for (int i = 1; i <= n; i ++)
        cin >> a[i], vals.push_back(a[i]), par[i] = -1, sm[i] = a[i], alive[i].insert(i);

    for (int i = 0; i < m; i ++){
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
        edges.push_back({max(a[u], a[v]), {u, v}});
    }
    sort(edges.begin(), edges.end());
    sort(vals.begin(), vals.end());
    vals.resize(unique(vals.begin(), vals.end()) - vals.begin());

    for (auto [w, E] : edges){
        auto [u, v] = E;
        merge(u, v, w);
    }

    for (int v = 1; v <= n; v ++){
        if (alive[root(v)].find(v) == alive[root(v)].end())
            cout << '0';
        else
            cout << '1';
    }
    cout << endl;
}

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