Submission #1261325

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261325		phamducluong	Race (IOI11_race)	C++20	Compilation error	0 ms	0 KiB

race

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>

//using namespace __gnu_pbds;
using namespace std;
using ll=long long;
//typedef tree<int,null_type,less_equal<int>,rb_tree_tag, tree_order_statistics_node_update> ordered_set;
#define mem(a,x)       memset(a,x,sizeof(a))
#define fast(s)        s.reserve(2000); s.max_load_factor(0.5);
#define F              first
#define S              second
#define pii            pair <int, int>
#define all(p)         p.begin(), p.end()
template<typename T> bool maximum(T &A, const T &B) {return A<B? A=B, true: false;}
template<typename T> bool minimum(T &A, const T &B) {return A>B? A=B, true: false;}
const int mod=998244353;
const int base=2999;
const int INF=1e9;
const int N=2e5+2, LOG=30, M=1e6+5;
int n, k, cnt[N], mn[M];
ll res;
bool del[N];
vector<pii> e[N];
void file()
{
    #define task "codeforces"
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}
void Count(int u, int pre)
{
    cnt[u]=1;
    for(auto [v,_]: e[u])
    {
        if(v==pre || del[v]) continue;
        Count(v,u);
        cnt[u]+=cnt[v];
    }
}
int centroid(int u, int pre, int n)
{
    for(auto [v,_]: e[u])
    {
        if(v==pre || del[v]) continue;
        if(cnt[v]>n/2) return centroid(v,u,n);
    }
    return u;
}
void DFS(int u, int pre, int d, int len)
{
    if(d==k) minimum(res,(ll)len);
    if(d>k) return;
    minimum(res,(ll)len+mn[k-d]);
    for(auto [v,w]: e[u])
    {
        if(v==pre || del[v]) continue;
        DFS(v,u,d+w,len+1);
    }
}
void update(int u, int pre, int d, int len, bool ok)
{
    if(d>k) return;
    if(ok) minimum(mn[d],len);
    else mn[d]=INF;
    for(auto [v,w]: e[u])
    {
        if(v==pre || del[v]) continue;
        update(v,u,d+w,len+1,ok);
    }
}
void calc(int u)
{
    Count(u,0);
    u=centroid(u,0,cnt[u]);
    for(auto [v,w]: e[u])
    {
        if(del[v]) continue;
        DFS(v,u,w,1);
        update(v,u,w,1,1);
    }
    for(auto [v,w]: e[u])
    {
        if(del[v]) continue;
        update(v,u,w,1,0);
    }
    del[u]=1;
    for(auto [v,_]: e[u])
    {
        if(del[v]) continue;
        calc(v);
    }
}
void Solve()
{
    cin>>n>>k;
    for(int i=1; i<n; ++i)
    {
        int u, v, w; cin>>u>>v>>w;
        e[u].push_back({v,w});
        e[v].push_back({u,w});
    }
    res=INF;
    fill(mn,mn+M,INF);
    calc(0);
    cout<<(res==INF? -1: res);
}

signed main()
{
    file();
    Solve();
    return 0;
}

Compilation message (stderr)

race.cpp: In function 'void file()':
race.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
race.cpp:30:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccsndfou.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccz4jTnX.o:race.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccsndfou.o: in function `main':
grader.cpp:(.text.startup+0x28): undefined reference to `best_path(int, int, int (*) [2], int*)'
collect2: error: ld returned 1 exit status