Submission #1103532

#	Time	Username	Problem	Language	Result	Execution time	Memory
1103532		KasymK	Commuter Pass (JOI18_commuter_pass)	C++17	31 / 100	280 ms	25080 KiB

commuter_pass

#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 ll INF = 1e18;
ll dis[N], diss[N];
int n;
 
void dij(int s, vector<vector<pii>> &adjx){
    for(int i = 1; i <= n; ++i)
        dis[i] = INF;
    priority_queue<pli, vector<pli>, greater<pli>> pq;
    pq.push({0, s});
    dis[s] = 0;
    while(!pq.empty()){
        int x = pq.top().ss;
        ll val = pq.top().ff;
        pq.pop();
        if(dis[x] != val)
            continue;
        tr(it, adjx[x]){
            int a = it->ff, w = it->ss;
            if(umin(dis[a], dis[x]+w))
                pq.push({dis[a], a});
        }
    }
}
 
int main(){
    vector<vector<pii>> adj, adj2;
    int m, s, t, u, v;
    scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
    adj.assign(n+1, {});
    adj2.assign(n+1, {});
    using node = tuple<int, int, int>;
    vector<node> A;
    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});
        A.pb({a, b, c});
    }
    dij(s, adj);
    for(int i = 1; i <= n; ++i)
        diss[i] = dis[i];
    dij(t, adj);
    for(auto &i : A){
        int a, b, c;
        tie(a, b, c) = i;
        bool did = 0, done = 0;
        if(diss[a]+dis[b]+c == diss[t])
            did = 1;
        if(dis[a]+diss[b]+c == diss[t])
            done = 1;
        if(did and done){
            adj2[a].pb({b, 0});
            adj2[b].pb({a, 0});
        }
        else if(!did and !done){
            adj2[a].pb({b, c});
            adj2[b].pb({a, c});
        }
        else if(did and !done){
            adj2[a].pb({b, 0});
            adj2[b].pb({a, c});
        }
        else{
            assert(!did and done);
            adj2[a].pb({b, c});
            adj2[b].pb({a, 0});
        }
    }
    dij(u, adj2);
    ll a0 = dis[v];
    dij(v, adj2);
    ll a00 = dis[u];
    ll answer = min(a0, a00);
    if(answer == INF)
        puts("-1");
    else
        printf("%lld\n", answer);
    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:50:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         scanf("%d%d%d", &a, &b, &c);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45