Submission #1184659

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184659		son2008	Airplane (NOI23_airplane)	C++20	100 / 100	190 ms	30396 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define task "task"
#define ii pair<int,int>
#define fi first
#define se second
#define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int,ii>
#define iiii pair<ii,ii>
#define base 29
#define eps 1e-8
int dx[]= {0LL,0LL,1,-1,1,1,-1,-1};
int dy[]= {1,-1,0LL,0LL,1,-1,1,-1};
const int maxn=4e5+1;
const int mod=1e9+7;
int dist[2][maxn],n,m,w[maxn];
vector<int>a[maxn];
void dijk(int st,int dist[])
{
    for(int i=1;i<=n;i++)dist[i]=1e18;
    dist[st]=0;
    priority_queue<ii,vector<ii>,greater<ii>>pq;
    pq.push({0LL,st});
    while(!pq.empty())
    {
        ii t=pq.top();
        pq.pop();
        if(t.fi!=dist[t.se])continue;
        for(int v:a[t.se])
        {
            int val=max(t.fi+1,w[v]);
            if(dist[v]>val)
            {
                dist[v]=val;
                pq.push({dist[v],v});
            }
        }
    }
}
void init()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++)cin>>w[i];
    for(int i=1;i<=m;i++)
    {
        int u,v;
        cin>>u>>v;
        a[u].push_back(v);
        a[v].push_back(u);
    }
    dijk(1,dist[0]);
    dijk(n,dist[1]);
    int ans=1e18;
    for(int i=1;i<=n;i++)
    {
        ans=min(ans,2*max(dist[0][i],dist[1][i]));
        for(int v:a[i])
        {
            ans=min(ans,2*max(dist[0][i],dist[1][v])+1);
        }
    }
    cout<<ans;
}
void process()
{

}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    init();
    process();
    cerr <<endl<< "TIME : " << clock() * 0.001 << "s" << endl ;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:79:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:80:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 10 / 10
• Subtask 3: 31 / 31
• Subtask 4: 37 / 37