Submission #1109597

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109597		dwuy	Stranded Far From Home (BOI22_island)	C++14	100 / 100	187 ms	43192 KiB

island

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

const int MX = 200005;
int f[MX];
int e[MX];
int n, m;
int a[MX];
vector<int> ans[MX];
vector<int> G[MX];

int fp(int u){
    return e[u] < 0? u : e[u] = fp(e[u]);
}

void unon(int u, int v){
    u = fp(u);
    v = fp(v);
    if(u == v) return;
    if(e[u] > e[v]) swap(u, v);
    e[u] += e[v];
    f[u] += f[v];
    e[v] = u;
    f[v] = 0;
    if(ans[u].size() < ans[v].size()) swap(ans[u], ans[v]);
    for(int x: ans[v]) ans[u].push_back(x);
    ans[v].clear();
}   

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin >> n >> m;
    for(int i=1; i<=n; i++) cin >> a[i];
    for(int i=1; i<=m; i++){
        int u, v;
        cin >> u >> v;
        G[u].push_back(v);
        G[v].push_back(u);
    }

    vector<int> b(n);
    for(int i=1; i<=n; i++) b[i - 1] = i;
    sort(b.begin(), b.end(), [&](const int &i, const int &j) -> bool { return a[i] < a[j]; });

    for(int i=1; i<=n; i++) f[i] = a[i];
    for(int i=1; i<=n; i++) e[i] = -1;
    for(int i=1; i<=n; i++) ans[i].push_back(i);
    bitset<MX> active = 0;
    for(int u: b){
        int cur = u;
        active[u] = 1;
        for(int v: G[u]) if(active[v] && cur != fp(v)){
            v = fp(v);
            if(f[v] < a[u]) ans[v].clear();
            unon(cur, v);
            cur = fp(cur);
        }
    }

    int u = fp(1);
    bitset<MX> homo = 0;
    for(int x: ans[u]) homo[x]  =1;
    for(int i=1; i<=n; i++) cout << homo[i];

    return 0;
}

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