Submission #1108425

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108425		KasymK	Evacuation plan (IZhO18_plan)	C++17	54 / 100	237 ms	28520 KiB

plan

#include "bits/stdc++.h"
using namespace std;
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define tr(i, c) for(auto i = c.begin(); i != c.end(); ++i)
#define wr puts("----------------")
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const int N = 1e5+5;
const int INF = 1e9;
vector<pii> adj[N];
int dis[N];
bool vis[N];

int main(){
    // freopen("file.txt", "r", stdin);
    int n, m;
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= n; ++i)
        dis[i] = INF;
    for(int i = 1; i <= m; ++i){
        int a, b, c;
        scanf("%d%d%d", &a, &b, &c);
        adj[a].pb({b, c});
        adj[b].pb({a, c});
    }
    int k;
    scanf("%d", &k);
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    for(int i = 1; i <= k; ++i){
        int x;
        scanf("%d", &x);
        dis[x] = 0;
        pq.push({0, x});
    }
    while(!pq.empty()){
        int x = pq.top().ss, val = pq.top().ff;
        pq.pop();
        if(dis[x] != val)
            continue;
        tr(it, adj[x]){
            int a = it->ff, w = it->ss;
            if(umin(dis[a], dis[x]+w))
                pq.push({dis[a], a});
        }
    }
    int a1, a2;
    auto check = [&](int ad) -> bool {
        for(int i = 1; i <= n; ++i)
            vis[i] = 0;
        queue<int> q;
        q.push(a1);
        vis[a1] = 1;
        while(!q.empty()){
            int x = q.front();
            q.pop();
            tr(it, adj[x]){
                if(it->ff==a2)
                    return 1;
                if(!vis[it->ff] and dis[it->ff]>=ad)
                    vis[it->ff] = 1, q.push(it->ff);
            }
        }
        return 0;
    };
    int Q, same;
    scanf("%d", &Q);
    same = Q;
    while(Q--){
        int s, t;
        scanf("%d%d", &s, &t);
        a1 = s, a2 = t;
        if(same==1 or n<=20){
            int l = 0, r = 1e9, answer = 1e9;
            while(l <= r){
                int mid = (l+r)>>1;
                if(check(mid))
                    l = mid+1, answer = mid;
                else
                    r = mid-1;
            }
            printf("%d\n", min({answer, dis[s], dis[t]}));
            continue;
        }
        printf("%d\n", min(dis[s], dis[t]));
    }
    return 0;
}

Compilation message (stderr)

plan.cpp: In function 'int main()':
plan.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
plan.cpp:29:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         scanf("%d%d%d", &a, &b, &c);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~
plan.cpp:34:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     scanf("%d", &k);
      |     ~~~~~^~~~~~~~~~
plan.cpp:38:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |         scanf("%d", &x);
      |         ~~~~~^~~~~~~~~~
plan.cpp:73:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     scanf("%d", &Q);
      |     ~~~~~^~~~~~~~~~
plan.cpp:77:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |         scanf("%d%d", &s, &t);
      |         ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 0 / 46