Submission #294990

#	Time	Username	Problem	Language	Result	Execution time	Memory
294990		thebes	Ferries (NOI13_ferries)	C++14	40 / 40	364 ms	17832 KiB

ferries

#include <bits/stdc++.h>
using namespace std;

const int MN = 1e5+5;
int N, M, i, x, y, W, dist[MN];
vector<int> adj[MN], w[MN];

typedef pair<int,int> pii;
struct pq{bool operator()(const pii&i,const pii&j){return i.second>j.second;}};
priority_queue<pii,vector<pii>,pq> q;

int main(){
    for(scanf("%d%d",&N,&M),i=1;i<=M;i++){
        scanf("%d%d%d",&x,&y,&W);
        adj[y].push_back(x);
        w[x].push_back(W);
    }
    for(i=1;i<=N;i++) sort(w[i].begin(),w[i].end(),[](int i,int j){return i<j;});
    memset(dist,-1,sizeof(dist));
    q.push({N,0});
    while(q.size()){
        auto v=q.top(); q.pop();
        if(dist[v.first]!=-1) continue;
        else dist[v.first]=v.second;
        for(auto e : adj[v.first]){
            W = w[e].back();
            if(dist[e]==-1){
                w[e].pop_back();
                q.push({e, W+v.second});
            }
        }
    }
    printf("%d\n",dist[1]);
    return 0;
}

Compilation message (stderr)

ferries.cpp: In function 'int main()':
ferries.cpp:13:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   13 |     for(scanf("%d%d",&N,&M),i=1;i<=M;i++){
      |         ~~~~~^~~~~~~~~~~~~~
ferries.cpp:14:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |         scanf("%d%d%d",&x,&y,&W);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12