제출 #1044742

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1044742		vjudge1	Evacuation plan (IZhO18_plan)	C++17	100 / 100	334 ms	59620 KiB

plan

#include <bits/stdc++.h>
#define faster cin.tie(0)->sync_with_stdio(0);
#define task "D"
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pdd pair<double, double>
#define fi first
#define se second
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define FOD(i, a, b) for(int i = a; i >= b; --i)
#define FOU(a, b) for(auto& a : b)
#define pb push_back
#define BIT(x, i) ((x >> i) & 1)
#define oo 1e9
#define OO 1e18
using namespace std;

const int N = 1e5 + 5;
ll n, m, x, y, w, k, q;
ll a[N], p[N], parent[N], s[N], id[N];
vector<pll> adj[N];
set<ll> sz[N];
ll dist[N];
bool mark[N];

bool cmp(ll &a, ll &b) {
    return dist[a] > dist[b];
}

void dijstra() {
    FOR(i, 1, n) dist[i] = OO;

    priority_queue<pll, vector<pll>, greater<pll>> pq;

    FOR(i, 1, k) {
        dist[a[i]] = 0;
        pq.push({0, a[i]});
    }

    while(!pq.empty()) {
        ll u = pq.top().se;
        pq.pop();

        if(mark[u]) continue;

        mark[u] = 1;
        FOU(v, adj[u]) {
            ll it = v.fi;
            ll w = v.se;
            if(dist[it] > dist[u] + w) {
                dist[it] = dist[u] + w;
                pq.push({dist[it], it});
            }
        }
    }
}

ll find_set(ll &u) {
    if(u == parent[u]) return u;
    return parent[u] = find_set(parent[u]);
}

void union_set(ll u, ll v) {
    u = find_set(u);
    v = find_set(v);

    if(u == v) return;

    if(s[u] < s[v]) swap(u, v);

    parent[v] = u;
    s[u] += s[v];
    FOU(it, sz[v]) {
        if(sz[u].find(it) != sz[u].end()) {
            sz[u].erase(it);
            p[it] = w;

        } else {
            sz[u].insert(it);
        }
    }
}

int main() {
    faster
    if(fopen(task ".inp", "r")) {
        freopen(task ".inp", "r", stdin);
        freopen(task ".out", "w", stdout);
    }

    cin >> n >> m;
    while(m--) {
        cin >> x >> y >> w;
        adj[x].pb({y, w});
        adj[y].pb({x, w});
    }
    cin >> k;
    FOR(i, 1, k) cin >> a[i];

    dijstra();

    cin >> q;
    FOR(i, 1, q) {
        cin >> x >> y;
        sz[x].insert(i);
        sz[y].insert(i);
    }

    FOR(i, 1, n) {
        id[i] = i;
        parent[i] = i;
        s[i] = i;
    }

    sort(id + 1, id + n + 1, cmp);
    memset(mark, 0, sizeof mark);

    FOR(i, 1, n) {
        x = id[i];
        mark[x] = 1;
        w = dist[x];
        FOU(it, adj[x]) {
            y = it.fi;
            if(mark[y]) {
                union_set(x, y);
            }
        }
    }

    FOR(i, 1, q) {
        cout << p[i] << "\n";
    }

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

plan.cpp: In function 'int main()':
plan.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen(task ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
plan.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(task ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46