Submission #601781

#	Time	Username	Problem	Language	Result	Execution time	Memory
601781		JeanBombeur	Stranded Far From Home (BOI22_island)	C++17	0 / 100	381 ms	524288 KiB

island

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

const int MAX_VILLAGE = (2e5);

vector <int> Adj[MAX_VILLAGE];

long long Size[MAX_VILLAGE];

pair <int, int> Sorted[MAX_VILLAGE];
bool Vu[MAX_VILLAGE];

long long Dsu[MAX_VILLAGE];
bool Valid[MAX_VILLAGE];

int nbVillages, nbRoads;

int Find(int a) {
    if (Dsu[a] < 0)
        return a;
    int p = Find(Dsu[a]);
    Valid[a] &= Valid[Dsu[a]];
    return Dsu[a] = p;
}

void Union(int old, int big) {
    old = Find(old);
    if (- Dsu[old] < Size[big])
        Valid[old] = false;
    Dsu[big] = Dsu[old] - Size[big];
    Dsu[old] = big;
    return;
}

void Read() {
    scanf("%d %d", &nbVillages, &nbRoads);
    for (int i = 0; i < nbVillages; i ++)
    {
        Valid[i] = true;
        scanf("%lld", &Size[i]);
        Sorted[i] = {Size[i], i};
        Dsu[i] = - Size[i];
    }
    sort(Sorted, Sorted + nbVillages);
    for (int i = 0; i < nbRoads; i ++)
    {
        int a, b;
        scanf("%d %d", &a, &b);
        Adj[-- a].push_back(-- b);
        Adj[b].push_back(a);
    }
    return;
}

void Solve() {
    for (int i = 0; i < nbVillages; i ++)
    {
        int cur = Sorted[i].second;
        Vu[cur] = true;
        for (int dest : Adj[cur])
        {
            if (Vu[dest])
                Union(dest, cur);
        }
    }
    for (int i = 0; i < nbVillages; i ++)
    {
        printf("%c", Valid[i] ? '1' : '0');
    }
    printf("\n");
    return;
}

int main() {
    Read();
    Solve();
    return 0;
}

Compilation message (stderr)

island.cpp: In function 'void Read()':
island.cpp:39:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |     scanf("%d %d", &nbVillages, &nbRoads);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
island.cpp:43:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |         scanf("%lld", &Size[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~
island.cpp:51:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         scanf("%d %d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~~

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