답안 #986251

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
986251	2024-05-20T07:01:36 Z	chautanphat	경주 (Race) (IOI11_race)	C++14	컴파일 오류	0 ms	0 KB

race

#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 1, W = 1e6 + 1;
int n, k, child[N], f[W], ans = N;
bool del[N];
vector<pair<int, int>> a[N];

void cntSize(int u, int pre = 0)
{
    child[u] = 1;
    for (int i = 0; i < (int)a[u].size(); i++)
    {
        int v = a[u][i].first;
        if (v == pre || del[v]) continue;
        cntSize(v, u);
        child[u] += child[v];
    }
}

int centroid(int u, int sz, int pre = 0)
{
    for (int i = 0; i < (int)a[u].size(); i++)
    {
        int v = a[u][i].first;
        if (v != pre && !del[v] && child[v] > sz/2) return centroid(v, sz, u);
    }
    return u;
}

void cal(int u, int dis, int mode, int pre = 0, int h = 1)
{
    if (dis > k) return;
    if (!mode)
        ans = min(ans, h+f[k-dis]);
    else f[dis] = min(f[dis], h);
    for (int i = 0; i < (int)a[u].size(); i++)
    {
        int v = a[u][i].first, w = a[u][i].second;
        if (del[v] || v == pre) continue;
        cal(v, dis+w, mode, u, h+1);
    }
}

void reset(int u, int dis, int pre = 0)
{
    f[dis] = N;
    for (int i = 0; i < (int)a[u].size(); i++)
    {
        int v = a[u][i].first, w = a[u][i].second;
        if (del[v] || v == pre) continue;
        reset(v, dis+w, u);
    }
}

void decompose(int u)
{
    cntSize(u);
    int root = centroid(u, child[u]);
    del[root] = 1;

    for (int i = 0; i < (int)a[root].size(); i++)
    {
        int v = a[root][i].first, w = a[root][i].second;
        if (del[v]) continue;
        cal(v, w, 0);
        cal(v, w, 1);
    }

    for (int i = 0; i < (int)a[root].size(); i++)
    {
        int v = a[root][i].first, w = a[root][i].second;
        if (del[v]) continue;
        reset(v, w);
    }

    for (int i = 0; i < (int)a[root].size(); i++)
        if (!del[a[root][i].first]) decompose(a[root][i].first);
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> n >> k;
    for (int i = 1; i <= k; i++) f[i] = N;
    for (int i = 1; i < n; i++)
    {
        int u, v, l;
        cin >> u >> v >> l;
        a[++u].push_back({++v, l});
        a[v].push_back({u, l});
    }

    decompose(1);

    cout << (ans == N ? -1 : ans);
    return 0;
}

Compilation message

/usr/bin/ld: /tmp/ccH20CTp.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccRmUzRs.o:grader.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccRmUzRs.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