Submission #461177

#	Time	Username	Problem	Language	Result	Execution time	Memory
461177		Killer2501	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	391 ms	27192 KiB

commuter_pass

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define task "asd"
#define pll pair<ll, ll>
#define pii pair<pll, ll>
#define fi first
#define se second

using namespace std;
const ll mod = 1e15+7;
const ll N = 2e5+5;
const int base = 313;
ll n, m, t, k, T, ans, tong, a[N], b[N], s, u, v, d[N][4], dp[N][4];
vector<pll> adj[N];
vector<ll> kq;

ll pw(ll k, ll n)
{
    ll total = 1;
    for(; n; n >>= 1)
    {
        if(n & 1)total = total * k % mod;
        k = k * k % mod;
    }
    return total;
}
void dij(ll ui, ll id)
{
    for(int i = 1; i <= n; i ++)d[i][id] = mod;
    priority_queue< pll, vector<pll>, greater<pll> > pq;
    pq.push({0, ui});
    d[ui][id] = 0;
    while(!pq.empty())
    {
        pll u = pq.top();
        pq.pop();
        if(u.fi != d[u.se][id])continue;
        for(pll v : adj[u.se])
        {
            if(d[v.se][id] > u.fi + v.fi)
            {
                d[v.se][id] = u.fi + v.fi;
                pq.push({d[v.se][id], v.se});
            }
        }
    }
}
void sol()
{
    cin >> n >> m >> s >> t >> u >> v;
    for(int i = 1; i <= m; i ++)
    {
        ll x, y, w;
        cin >> x >> y >> w;
        adj[x].pb({w, y});
        adj[y].pb({w, x});
    }
    dij(s, 0);
    dij(u, 1);
    dij(v, 2);
    queue<ll> q;
    for(int i = 1; i <= n; i ++)
    {
        dp[i][0] = dp[i][1] = dp[i][2] = mod;
        for(pll vi : adj[i])
        {
            if(d[i][0] + vi.fi == d[vi.se][0])++a[vi.se];
        }
    }
    q.push(s);
    while(!q.empty())
    {
        ll ui = q.front();
        q.pop();
        dp[ui][0] = min(dp[ui][0], d[ui][1]);
        dp[ui][1] = min(dp[ui][1], d[ui][2]);
        dp[ui][2] = min(dp[ui][2], min(dp[ui][0] + d[ui][2], dp[ui][1] + d[ui][1]));
        for(pll vi : adj[ui])
        {
            if(d[vi.se][0] == d[ui][0] + vi.fi)
            {
                --a[vi.se];
                dp[vi.se][0] = min(dp[vi.se][0], dp[ui][0]);
                dp[vi.se][1] = min(dp[vi.se][1], dp[ui][1]);
                dp[vi.se][2] = min(dp[vi.se][2], dp[ui][2]);
                if(!a[vi.se])q.push(vi.se);
            }
        }
    }
    cout << min(dp[t][2], d[u][2]);
}
int main()
{
    if(fopen(task".INP", "r"))
    {
       freopen(task".INP", "r", stdin);
       freopen(task".OUT", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int ntest = 1;
    //cin >> ntest;
    while(ntest -- > 0)
    sol();
}
/*
5 1
1 2
2 3
3 4
4 5
*/

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:97:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |        freopen(task".INP", "r", stdin);
      |        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:98:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   98 |        freopen(task".OUT", "w", stdout);
      |        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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