Submission #337792

#	Time	Username	Problem	Language	Result	Execution time	Memory
337792		BeanZ	Evacuation plan (IZhO18_plan)	C++14	100 / 100	2308 ms	57748 KiB

plan

// I_Love_LPL
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int N = 1e5 + 50;
long long mod = 1e9 + 7;
const int lim = 700;
const int lg = 18;
const int base = 311;
const long double eps = 1e-6;
vector<pair<ll, ll>> node[N];
struct viet{
    ll tt, id, type;
    bool operator <(const viet &o) const{
        if (tt == o.tt) return type < o.type;
        return tt > o.tt;
    }
};
ll d[N], l[N], h[N], md[N], p[N], s[N], t[N], ans[N];
ll find_set(ll u){
    if (p[u] < 0) return u;
    return p[u] = find_set(p[u]);
}
void dsu(ll u, ll v){
    u = find_set(u);
    v = find_set(v);
    if (u == v) return;
    if (p[u] > p[v]) swap(u, v);
    p[u] += p[v];
    p[v] = u;
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("tests.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++){
        ll u, v, c;
        cin >> u >> v >> c;
        node[u].push_back({v, c});
        node[v].push_back({u, c});
    }
    ll k;
    cin >> k;
    for (int i = 1; i <= n; i++) d[i] = 1e18;
    priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> pq;
    for (int i = 1; i <= k; i++){
        ll u;
        cin >> u;
        d[u] = 0;
        pq.push({0, u});
    }
    while (pq.size()){
        pair<ll, ll> x = pq.top();
        pq.pop();
        if (d[x.second] != x.first) continue;
        for (auto j : node[x.second]){
            if (d[j.first] > (j.second + x.first)){
                d[j.first] = j.second + x.first;
                pq.push({d[j.first], j.first});
            }
        }
    }
    ll q;
    cin >> q;
    for (int i = 1; i <= q; i++){
        cin >> s[i] >> t[i];
        l[i] = 0, h[i] = 1e9;
    }
    while (true){
        bool flag = false;
        vector<viet> Q;
        for (int i = 1; i <= q; i++){
            if (l[i] > h[i]) continue;
            md[i] = (l[i] + h[i]) >> 1;
            flag = true;
            Q.push_back({md[i], i, 1});
        }
        if (!flag) break;
        for (int i = 1; i <= n; i++){
            Q.push_back({d[i], i, 0});
        }
        memset(p, -1, sizeof(p));
        sort(Q.begin(), Q.end());
        for (auto j : Q){
            if (j.type == 0){
                for (auto to : node[j.id]){
                    if (d[to.first] >= d[j.id]) dsu(to.first, j.id);
                }
            } else {
                ll id = j.id;
                if (find_set(s[id]) == find_set(t[id])) ans[id] = 1;
                else ans[id] = 0;
            }
        }
        for (int i = 1; i <= q; i++){
            if (ans[i] == 1) l[i] = md[i] + 1;
            else h[i] = md[i] - 1;
        }
    }
    for (int i = 1; i <= q; i++) cout << h[i] << endl;
}
/*
9 12
1 9 4
1 2 5
2 3 7
2 4 3
4 3 6
3 6 4
8 7 10
6 7 5
5 8 1
9 5 7
5 4 12
6 8 2
2
4 7
5
1 6
5 3
4 8
5 8
1 5
Ans:

Out:
*/

Compilation message (stderr)

plan.cpp: In function 'int main()':
plan.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   37 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
plan.cpp:38:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   38 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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