oj.uz

답안 #877037

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
877037 2023-11-22T18:37:54 Z andrei_iorgulescu Stranded Far From Home (BOI22_island) C++14
10 / 100
 753 ms 154244 KB 
#include <bits/stdc++.h>

using namespace std;

#define int long long

struct grup
{
    vector<int>noduri_alive;
    int nr_oameni;
    multiset<pair<int,int>> edges;
};

int n,m,s[200005];
vector<pair<int,int>>G[200005];
int t[200005],sz[200005];
grup g[200005];
bool sol_finala[200005];

bool cmp(int x,int y)
{
    if (g[x].nr_oameni != g[y].nr_oameni)
        return g[x].nr_oameni < g[y].nr_oameni;
    return x < y;
}

multiset<int,decltype(cmp)*>st(cmp);

int ancestor(int nod)
{
    while (nod != t[nod])
        nod = t[nod];
    return nod;
}

void join(int x,int y)
{
    if (sz[x] < sz[y])
        swap(x,y);
    sz[x] += sz[y];
    t[y] = x;
    g[x].nr_oameni += g[y].nr_oameni;
    for (auto it : g[y].noduri_alive)
        g[x].noduri_alive.push_back(it);
    for (auto it : g[y].edges)
        g[x].edges.insert(it);
    g[y].nr_oameni = 0;
    g[y].noduri_alive.clear();
    g[y].edges.clear();
    st.insert(x);
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        cin >> s[i];
    for (int i = 1; i <= m; i++)
    {
        int x,y;
        cin >> x >> y;
        G[x].push_back({s[y],y});
        G[y].push_back({s[x],x});
    }
    for (int i = 1; i <= n; i++)
    {
        t[i] = i;
        sz[i] = 1;
        g[i].noduri_alive = {i};
        g[i].nr_oameni = s[i];
        for (auto it : G[i])
            g[i].edges.insert(it);
        st.insert(i);
    }
    while (st.size() >= 2)
    {
        /*for (auto it : st)
        {
            cout << it << ' ' << g[it].nr_oameni << endl;
            for (auto itt : g[it].noduri_alive)
                cout << itt << ' ';
            cout << endl;
            for (auto itt : g[it].edges)
                cout << itt.first << ' ' << itt.second << endl;
            cout << endl;
        }
        cout << endl;*/
        int nod = *st.begin();
        //cout << nod << endl;
        while (true)
        {
            pair<int,int>aux = *(g[nod].edges.begin());
            if (ancestor(aux.second) == nod)
                g[nod].edges.erase(g[nod].edges.begin());
            else
                break;
        }
        pair<int,int>aux = *(g[nod].edges.begin());
        //cout << aux.first << ' ' << aux.second << endl;
        g[nod].edges.erase(g[nod].edges.begin());
        if (aux.first > g[nod].nr_oameni)
        {
            //cout << "caz1 " << nod << endl;
            st.erase(st.find(nod));
            g[nod].noduri_alive.clear();
        }
        else
        {
            //cout << "caz2 " << nod << ' ';
            int x = aux.second;
            x = ancestor(x);
            //cout << x << endl;
            st.erase(st.find(nod));
            //cout << st.size() << endl;
            if (st.find(x) != st.end())
                st.erase(st.find(x));
            join(nod,x);
        }
    }
    for (auto it : st)
    {
        for (auto x : g[it].noduri_alive)
            sol_finala[x] = true;
    }
    for (int i = 1; i <= n; i++)
    {
        if (sol_finala[i] == false)
            cout << 0;
        else
            cout << 1;
    }
    return 0;
}

/**
fiecare muchie devine defapt doua muchii, una x -> y cu cost s[y] si una y -> x cu cost s[x]

iau grupul cu macar un nod alive cu cei mai putini oameni si muchia lui spre un nod cu s cat mai mic
daca nu le pot conecta, marchez ca not alive toate nodurile alive din grup
daca le pot conecta, fac un small to large pe noduri (nu conteaza daca alive sau nu) pentru a le uni

ok, idee penala, acum ramane cum implementez

tin un dsu pentru grupuri, iar in tatal grupului tin:
-nodurile alive din grup
-cate alive am
-cati oameni am
-muchiile, sortate dupa cost

imi pot tine un set cu tatii grupurilor cu macar un nod alive, pentru fiecare retinand:
-ofc nodul tata
-numarul de oameni

o sa am ceva gen:

while (setul mai are >= 2 grupuri alive)
{
    iau si eu grupul din set cu numar minim de oameni
    lui ii iau muchia minima pentru care nu sunt ambele noduri conectate de muchie in grupul lui nod
    daca pe muchia asta nu pot conecta, atunci scot din set nodul nod (si atat)
    daca pe muchia asta pot conecta, am doua cazuri:
    1. nodul de care conectez nu e alive -> il scot pe asta din set, le dau join si bag combinata lor in set
    2. nodul de care conectez e alive -> ii scot pe ambii din set, le dau join si bag combinata lor in set
}

apoi, din grupul care mi-a mai ramas singur in set, afisez alea alive
**/

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 24920 KB Output is correct
2 Correct 4 ms 24924 KB Output is correct
3 Correct 5 ms 25080 KB Output is correct
4 Runtime error 24 ms 51476 KB Execution killed with signal 11
5 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 24920 KB Output is correct
2 Correct 5 ms 24924 KB Output is correct
3 Correct 655 ms 85496 KB Output is correct
4 Correct 403 ms 78380 KB Output is correct
5 Correct 656 ms 81132 KB Output is correct
6 Correct 662 ms 82884 KB Output is correct
7 Correct 691 ms 83032 KB Output is correct
8 Correct 423 ms 78372 KB Output is correct
9 Correct 442 ms 82648 KB Output is correct
10 Correct 288 ms 75704 KB Output is correct
11 Correct 379 ms 79604 KB Output is correct
12 Correct 577 ms 78796 KB Output is correct
13 Correct 390 ms 78124 KB Output is correct
14 Correct 397 ms 78280 KB Output is correct
15 Correct 383 ms 80248 KB Output is correct
16 Correct 275 ms 77252 KB Output is correct

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 24924 KB Output is correct
2 Runtime error 753 ms 153344 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 24924 KB Output is correct
2 Runtime error 266 ms 154244 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -

Subtask #5
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 24920 KB Output is correct
2 Correct 4 ms 24924 KB Output is correct
3 Correct 5 ms 25080 KB Output is correct
4 Runtime error 24 ms 51476 KB Execution killed with signal 11
5 Halted 0 ms 0 KB -