Submission #92139

#	Time	Username	Problem	Language	Result	Execution time	Memory
92139		karma	Commuter Pass (JOI18_commuter_pass)	C++11	100 / 100	496 ms	26144 KiB

commuter_pass

#include<bits/stdc++.h>
#define For(i, a, b)  for(int i = a, _b = b; i <= _b; ++i)
#define Ford(i, a, b) for(int i = a, _b = b; i >= _b; --i)
#define FileName      "test"
#define ll            long long
#define ld            long double
#define ull           unsigned long long
#define Print(x)      cerr << #x << "is " << x << '\n';
#define pb            push_back
#define X             first
#define Y             second
//#define Karma

using namespace std;

template<typename T> inline void Cin(T &x)
{
    char c;
    T sign = 1;
    x = 0;
    for (c = getchar(); c < '0' || c > '9'; c = getchar())
        if (c == '-') sign = -1;
    for (; c >= '0' && c <= '9'; c = getchar())
        x = x * 10 + c - '0';
    x *= sign;
}
template <typename T> inline void Out(T x) {if(x > 9) Out(x / 10); putchar(x % 10 + '0');}
template <typename T> inline void Cout(T x, char c) {if(x < 0) putchar('-'); x = abs(x); Out(x); putchar(c);}
template <typename T, typename... Args> inline void Cin(T& a, Args&... args) {Cin(a);Cin(args...);}
template <typename T, typename... Args> inline void Cout(T a, char c, Args... args) {Cout(a, c);Cout(args...);}

typedef pair<int, int> pii;
typedef pair<ll, int> plli;
const int N = 1e5 + 7;
const ll oo = (ll)1e18 + 7;

struct TEdge
{
    int u, v; ll w;
} _e[N * 2];
typedef TEdge* PEdge;
PEdge e;
ll res;
queue<int> q;
vector<ll> d[4], dis[4];
vector<int> g[N];
vector<PEdge> a[N];
int n, m, s, t, u, v, in[N];
priority_queue<plli, vector<plli>, greater<plli>> pq;

void Dijkstra(int s, vector<ll>& d)
{
    d.resize(n + 1);
    for(int i = 0; i <= n; ++i) d[i] = oo;
    pq.push({0, s});
    d[s] = 0;
    while(!pq.empty())
    {
        plli top = pq.top();
        pq.pop();
        if(d[top.Y] != top.X) continue;
        int u = top.Y;
        for(PEdge e: a[u])
        {
            int v = e -> u + e -> v - u;
            if(d[v] > d[u] + e -> w) d[v] = d[u] + e -> w, pq.push({d[v], v});
        }
    }
}

void Enter()
{
     Cin(n, m, s, t, u, v);
     e = _e;
     For(i, 1, m)
     {
         ++e;
         Cin(e -> u, e -> v, e -> w);
         a[e -> u].pb(e), a[e -> v].pb(e);
     }
     Dijkstra(s, d[0]), Dijkstra(t, d[1]);
     Dijkstra(u, d[2]), Dijkstra(v, d[3]);
     e = _e;
     For(i, 1, m)
     {
         ++e;
         if(d[0][e -> u] + e -> w + d[1][e -> v] == d[0][t])
            g[e -> v].pb(e -> u), ++in[e -> u];
         swap(e -> u, e -> v);
         if(d[0][e -> u] + e -> w + d[1][e -> v] == d[0][t])
            g[e -> v].pb(e -> u), ++in[e -> u];
     }
}

void Solve()
{
     dis[2] = d[2], dis[3] = d[3];
     res = d[2][v];
     q.push(t);
     while(!q.empty())
     {
         int x = q.front();
         q.pop();
         res = min(res, min(d[3][x] + dis[2][x], d[2][x] + dis[3][x]));
         for(int y: g[x])
         {
             dis[3][y] = min(dis[3][x], dis[3][y]);
             dis[2][y] = min(dis[2][y], dis[2][x]);
             --in[y];
             if(in[y] == 0) q.push(y);
         }
     }
     cout << res;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
#ifdef Karma
    freopen(FileName".inp", "r", stdin);
    freopen(FileName".out", "w", stdout);
#endif // Karma

    Enter();
    Solve();

    return 0;
}

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