Submission #1256656

#	Time	Username	Problem	Language	Result	Execution time	Memory
1256656		hainam2k9	Olympic Bus (JOI20_ho_t4)	C++20	5 / 100	1095 ms	2888 KiB

ho_t4

#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 5e4+5;
const string NAME = "";
struct Edge{
    int to,weight,pos;
    bool dir;
    Edge(int a, int b, int c, bool d){
        to=a, weight=b, pos=c, dir=d;
    }
};
int n,m,cost[MAXN];
ll rs=1e18,dist1[205],distN[205];
bool cur[MAXN];
vector<Edge> adj[205];
void dijkstra(int u, ll dist[]){
    priority_queue<pair<ll,int>, vector<pair<ll,int>>, greater<pair<ll,int>>> pq;
    dist[u]=0, pq.ins(0,u);
    while(!pq.empty()){
        pair<ll,int> top = pq.top();
        pq.pop();
        if(top.fi>dist[top.se]) continue;
        for(Edge& e : adj[top.se])
            if(cur[e.pos]==e.dir&&dist[e.to]>top.fi+e.weight) dist[e.to]=top.fi+e.weight, pq.ins(dist[e.to],e.to);
    }
}
ll calc(){
    memset(dist1,0x3f,sizeof(dist1));
    memset(distN,0x3f,sizeof(distN));
    dijkstra(1,dist1);
    dijkstra(n,distN);
    return dist1[n]+distN[1];
}
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    cin >> n >> m;
    for(int i = 1; i<=m; ++i){
        int x,y,z;
        cin >> x >> y >> z >> cost[i];
        adj[x].pb(Edge(y,z,i,0)), adj[y].pb(Edge(x,z,i,1));
    }
    rs=calc();
    for(int i = 1; i<=m; ++i){
        cur[i]=1;
        rs=min(rs,calc()+cost[i]);
        cur[i]=0;
    }
    if(rs>=1e18) rs=-1;
    cout << rs;
}

Compilation message (stderr)

ho_t4.cpp: In function 'int main()':
ho_t4.cpp:3:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:54:45: note: in expansion of macro 'fo'
   54 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
ho_t4.cpp:3:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:54:45: note: in expansion of macro 'fo'
   54 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63