제출 #1155487

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1155487		CrabCNH	Stranded Far From Home (BOI22_island)	C++20	100 / 100	82 ms	13548 KiB

island

#include <bits/stdc++.h>

#define task   "BriantheCrab"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())

using namespace std;

template <class T> void mini (T &t, T f) {if (t > f) t = f;}
template <class T> void maxi (T &t, T f) {if (t < f) t = f;}

const int maxN = 2e5 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;

int n, m;
int a[maxN], par[maxN], mxSz[maxN];
bool aval[maxN];
vector <tuple <int, int, int>> all;

void init () {
    for (int i = 1; i <= n; i ++) {
        par[i] = i;
        mxSz[i] = a[i];
        aval[i] = false;
    }
}

int getRoot (int u) {
    if (par[u] == u) {
        return u;
    }
    int p = getRoot (par[u]);
    aval[u] |= aval[par[u]];
    return (par[u] = p);
}

void merge (int u, int v) {
    u = getRoot (u);
    v = getRoot (v);
    if (u == v) {
        return;
    }
    if (mxSz[v] < a[u]) {
        aval[v] = true;
    }
    par[v] = u;
    mxSz[u] += mxSz[v];
}

void solve () {
    cin >> n >> m;
    for (int i = 1; i <= n; i ++) {
        cin >> a[i];
    }
    init ();
    for (int i = 1; i <= m; i ++) {
        int u, v;
        cin >> u >> v;
        if (a[u] < a[v]) {
            swap (u, v);
        }
        all.push_back ({a[u], u, v});
    }
    sort (all.begin (), all.end ());
    for (auto [_, u, v] : all) {
        merge (u, v);        
    }
    for (int i = 1; i <= n; i ++) {
        getRoot (i);
        cout << (!aval[i] ? 1 : 0);
    }
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        solve ();
    } 
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

island.cpp: In function 'int main()':
island.cpp:83:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
island.cpp:84:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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