제출 #1305474

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1305474		sdfsdfsdf	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	18 ms	35620 KiB

commuter_pass

#include <bits/stdc++.h>
#include <iostream>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
#define vt vector
#define heap priority_queue
#define dq deque
#define maxN 500005
#define maxA 20000005
#define maxM 5005
#define fi first
#define se second
#define For(i, j, n) for(int i=(j);i<=(n);i++)
#define Forr(i, n, j) for(int i=(n);i>=(j);i--)
#define pb push_back
#define pf push_front
#define reset(x,val) memset((x),(val),sizeof(x))
#define bit(i,j) ((i>>j)&1ll)
#define mask(i) (1ll<<i)
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()
/* I LOVE WHAT IM DOING AND ILL KEEP DOING TS UNTIL I GET THERE, NOT JUST ABT CODING */
typedef __gnu_pbds::tree<int, __gnu_pbds::null_type, less<int>, __gnu_pbds::rb_tree_tag,
__gnu_pbds::tree_order_statistics_node_update> ordered_set;
typedef long long ll;
typedef pair<ll, ll> ii;
const string NAME = "c++";
void io() {ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);}
ll bpow(ll x, ll n, ll modd){if (n==0) return 1; ll s = bpow(x, n/2, modd); s = (s*s)%modd;
if (n%2) return (s*x)%modd; else return s%modd;}
ll pairing(ll x) {return x*(x-1)/2;}
ll sumto(ll x) {return x*(x+1)/2;}
const ll inf = (ll)1e18;
const ll neg_inf = -(ll)1e18;
const ll mod = 1e9+7;
/* modular inverse by bpow(x, mod -2)%mod*/
//------

//------
/* debugging tips
1. clear all data structure
2. clear var
3. check corner case
4. check loops
5. check mod
6. if clear, then avoid abusing built-in clear function.
7. making mistakes are tolerated but doing it twice is not, better KMS
*/
//any function here
ll S, T, U, V;
ll n, m;
struct Edge
{
    ll v, c;
};
struct Node
{
    ll u, d;
};
struct cmp
{
    bool operator() (Node a, Node b)
    {
        return a.d > b.d;
    }
};
vt<Edge> a[maxN];
vt<ll> parent[maxN], children[maxN];
ll dS[maxN], dU[maxN], dV[maxN];
bool ok[maxN];

void dij(ll dist[], ll s)
{
    heap<Node, vt<Node>, cmp> h;
    vt<bool> visited(n+1, false);
    For (i, 1, n) dist[i] = inf;
    dist[s] = 0;
    h.push({s, dist[s]});
    while(!h.empty())
    {
        Node x = h.top(); h.pop();
        ll u = x.u;
        if (visited[u])
            continue;

        visited[u] = true;
        for (Edge e:a[u])
        {
            ll v = e.v;
            ll c = e.c;
            if (dist[v]>dist[u]+c){
                dist[v] = dist[u]+c;
                if (s == S) {parent[v].clear(); parent[v].pb(u);}
                h.push({v, dist[v]});
            }
            else if (dist[v]==dist[u]+c)
            {
                if (s==S) parent[v].pb(u);
            }
        }
    }
}
ll bst[2][maxN];
ll dpF(ll u)
{
    if (bst[0][u]!=-1) return bst[0][u];
    ll mn = dV[u];
    for (int v:children[u])
    {
        mn = min(mn, dpF(v));
    }
    return bst[0][u] = mn;
}
ll dpB(ll u)
{
    if (bst[1][u]!=-1) return bst[1][u];
    ll mn = dV[u];
    for (int v:parent[u])
    {
        mn = min(mn, dpB(v));
    }
    return bst[1][u] = mn;
}
void solve()
{
    cin>>n>>m>>S>>T>>U>>V;
    For (i, 1, m)
    {
        ll u, v, c;
        cin>>u>>v>>c;
        a[u].pb({v, c});
        a[v].pb({u, c});
    }
    dij(dS, S);
    dij(dU, U);
    dij(dV, V);

    ll ans = dU[V];
    queue<ll> q; q.push(T);
    while(!q.empty())
    {
        ll u = q.front(); q.pop();
        if (!ok[u])
        {
            ok[u] = true;
            for (ll v:parent[u])
            {
                children[v].pb(u);
                q.push(v);
            }
        }
    }
    For (i, 1, n)
    {
        bst[0][i] = bst[1][i] = -1;
    }
    For (i, 1, n)
    {
        if (ok[i])
        {
            ans = min(ans, dU[i] + min(dpF(i), dpB(i)));
        }
    }
    cout<<ans<<endl;
}

int main()
{
    io();
    #ifndef ONLINE_JUDGE
        freopen((NAME + ".INP").c_str(), "r", stdin);
        freopen((NAME + ".OUT").c_str(), "w", stdout);
    #endif
    ll T = 1;
    //cin>>T;
    while(T--) solve();
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:172:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  172 |         freopen((NAME + ".INP").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:173:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  173 |         freopen((NAME + ".OUT").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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