| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 210642 | robinrst | 경주 (Race) (IOI11_race) | C++17 | 0 ms | 0 KiB |
이 제출은 이전 버전의 oj.uz에서 채점하였습니다. 현재는 제출 당시와는 다른 서버에서 채점을 하기 때문에, 다시 제출하면 결과가 달라질 수도 있습니다.
#include "algorithm"
#include "iostream"
#include "numeric"
#include "iomanip"
#include "cstring"
#include "math.h"
#include "bitset"
#include "string"
#include "vector"
#include "ctime"
#include "queue"
#include "stack"
#include "map"
#include "set"
#include "ext/pb_ds/assoc_container.hpp" // Common file
#include "ext/pb_ds/tree_policy.hpp" // Including tree_order_statistics_node_update
#include "ext/pb_ds/detail/standard_policies.hpp"
using namespace std;
using namespace __gnu_pbds;
#define f first
#define lgn 25
#define endl '\n'
#define sc second
#define N (int)2e5+5
#define pb push_back
#define mod 1000000007
#define ld long double
#define vi vector<int>
#define eb emplace_back
#define vpii vector<pii>
#define mii map<int,int>
#define int long long
#define pii pair<int,int>
#define pq priority_queue
#define BLOCK (int)sqrt(N)
#define test(x) while(x--)
#define all(x) begin(x),end(x)
#define allr(x) rbegin(x),rend(x)
#define fo(i,a,n) for(int i=a;i<n;i++)
#define rfo(i,n,a) for(int i=n;i>=a;i--)
#define FAST ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define time() cerr << "Time : " << (double)clock() / (double)CLOCKS_PER_SEC << "s\n"
#define PI acos(-1.0)
#define bug(...) __f (#__VA_ARGS__, __VA_ARGS__)
typedef tree< int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update >
OS ;
template <typename Arg1>
void __f (const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << endl; }
template <typename Arg1, typename... Args>
void __f (const char* names, Arg1&& arg1, Args&&... args)
{
const char* comma = strchr (names + 1, ',');
cout.write (names, comma - names) << " : " << arg1 << " | "; __f (comma + 1, args...);
}
inline void INP()
{
#ifndef ONLINE_JUDGE
freopen("input.txt","r",stdin);
freopen("output.txt","w",stdout);
#endif
}
const int inf = 0x3f3f3f3f;
const int INF = 0x3f3f3f3f3f3f3f3f;
int n,m,k,q,ans;
string s;
vpii adj[N];
int in[N],out[N],sz[N],Dep[N],sumNow[N],id[N];
bool big[N];
mii path;
void dfsSize(int i = 0, int p = -1)
{
static int clk = 0;
sz[i] = 1;
in[i] = ++clk;
id[clk] = i;
for( auto j : adj[i] )
{
if( j.f != p )
{
sumNow[j.f] = sumNow[i] + j.sc;
Dep[j.f] = Dep[i] + 1;
dfsSize(j.f , i);
sz[i] += sz[j.f];
}
}
out[i] = clk;
}
#define z id[k]
void add(int i, int x)
{
int sum = sumNow[i];
if( x == -1 ) path[sum] = 0;
else
{
int xx = path[sum];
if( xx == 0 ) xx = INF;
path[sum] = min( Dep[i] , xx );
}
}
void dfs(int i = 0 , int p = -1, bool keep = 0)
{
int mx = -1, bigChild = -1;
for( auto j : adj[i] )
{
if( j.f != p and mx < sz[j.f] ) mx = sz[j.f] , bigChild = j.f;
}
for( auto j : adj[i] )
{
if( j.f != p and j.f != bigChild ) dfs(j.f , i , 0);
}
if( ~bigChild ) dfs(bigChild , i , 1) , big[bigChild] = 1;
for( auto j : adj[i] )
{
if( j.f != p and !big[j.f] )
{
fo(k,in[j.f],out[j.f]+1)
{
int now = abs( sumNow[z] - sumNow[i] - m );
if( path[now] )
{
ans = min( ans , path[now] + (Dep[z] - Dep[i]) - Dep[i] );
// Minus Dep[i] in the end is because we have that added in path[now - k]
}
}
fo(k,in[j.f],out[j.f]+1) add( z , 1);
}
}
add(i ,1);
// for( auto j : path ) cout << j.f << '-' << j.sc << endl;
// cout << endl;
if( path[ sumNow[i] + m ] ) ans = min( ans , path[ sumNow[i] + m ] - Dep[i] ); // Minus Dep[i] beacuse that is already added in path[ sumNow[i] + k]
if( !keep )
{
fo(k,in[i],out[i]+1) add(z , -1);
}
}
void go()
{
cin >> n >> m;
ans = INF;
fo(i,0,n-1)
{
int u , v , w;
cin >> u >> v >> w;
adj[u].pb({ v, w} );
adj[v].pb({ u , w} );
}
dfsSize();
dfs();
if( ans == INF ) ans = -1;
cout << ans << endl;
}
int32_t main()
{
//INP();
FAST;
int t=1;
// cin>>t;
test(t) go();
}