Submission #969949

#	Time	Username	Problem	Language	Result	Execution time	Memory
969949		njoop	Evacuation plan (IZhO18_plan)	C++14	100 / 100	705 ms	64352 KiB

plan

#include <bits/stdc++.h>
#define pi pair<int, int>
#define ti tuple<int, int, int>
using namespace std;

int n, m, dis[100010], rt[100010], ans[100010], u, v, w, q, cu, cv, cw, s, t;
vector<pi> g[100010];
vector<int> st, en;
set<int> pa[100010];
priority_queue<pi, vector<pi>, greater<pi>> pq;
priority_queue<ti> ed;

int fr(int no) {
    if(rt[no] == no) return no;
    else return rt[no] = fr(rt[no]);
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> m;
    while(m--) {
        cin >> u >> v >> w;
        g[u].push_back({w, v});
        g[v].push_back({w, u});
        st.push_back(u);
        en.push_back(v);

    }
    fill(dis, dis+100010, 1e9);
    cin >> q;
    while(q--) {
        cin >> u;
        pq.push({0, u});
    }
    cin >> q;
    for(int i=1; i<=q; i++) {
        cin >> s >> t;
        pa[s].insert(i);
        pa[t].insert(i);
    }
    while(!pq.empty()) {
        cu = pq.top().second;
        cw = pq.top().first;
        pq.pop();
        if(dis[cu] <= cw) {
            continue;
        }
        dis[cu] = cw;
        for(auto i: g[cu]) {
            pq.push({i.first+cw, i.second});
        }
    }
    
    for(int i=0; i<st.size(); i++) {
        ed.push({min(dis[st[i]], dis[en[i]]), st[i], en[i]}); 
    }
    for(int i=0; i<=n; i++) {
        rt[i] = i;
    }
    while(!ed.empty()) {
        cw = get<0>(ed.top());
        cu = fr(get<1>(ed.top()));
        cv = fr(get<2>(ed.top()));
        ed.pop();
        if(rt[cu] == rt[cv]) continue;
        if(pa[cu].size() < pa[cv].size()) {
            swap(cu, cv);
        }
        for(auto i: pa[cv]) {
            if(pa[cu].count(i)) {
                ans[i] = cw;
                pa[cu].erase(i);
            } else {
                pa[cu].insert(i);
            }
        }
        rt[cv] = cu;
    }
    for(int i=1; i<=q; i++) {
        cout << ans[i] << "\n";
    }
    return 0;
}

Compilation message (stderr)

plan.cpp: In function 'int main()':
plan.cpp:54:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for(int i=0; i<st.size(); i++) {
      |                  ~^~~~~~~~~~

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