Submission #998251

#	Time	Username	Problem	Language	Result	Execution time	Memory
998251		cpptowin	Airplane (NOI23_airplane)	C++17	100 / 100	246 ms	64792 KiB

Main

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(),x.end()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
int n,m,a[maxn],l[maxn],r[maxn];
vi ke[maxn];
void dij(int inp,int d[],int n)
{
    fo(i,1,n) d[i] = inf;
    d[inp] = 0;
    priority_queue<pii,vii,greater<pii>> q;
    q.push({0,inp});
    while(q.size())
    {
        auto [du,u] = q.top();
        q.pop();
        if(d[u] != du) continue;
        for(int v : ke[u])
        {   
            int val = max(du + 1,a[v]);
            if(minimize(d[v],val))
            {
                q.push({d[v],v});
            }
        }
    }
}
pii edge[maxn];
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> m;
    fo(i,1,n) cin >> a[i];
    fo(i,1,m)
    {
        int u,v;
        cin >> u >> v;
        ke[u].pb(v);
        ke[v].pb(u);
        edge[i] = {u,v};
    }
    dij(1,l,n);
    dij(n,r,n);
    int ans = inf;
    fo(i,1,n) 
    {
        minimize(ans,max(l[i],r[i]) * 2);
    }
    fo(i,1,m)
    {
        auto [u,v] = edge[i];
        minimize(ans,max(l[u],r[v]) * 2 + 1);
        minimize(ans,max(r[u],l[v]) * 2 + 1);
    }
    cout << ans;
}

Compilation message (stderr)

Main.cpp:67:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   67 | main()
      | ^~~~
Main.cpp: In function 'int main()':
Main.cpp:72:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:73:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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