답안 #970408

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
970408	2024-04-26T13:36:16 Z	hoangbach	경주 (Race) (IOI11_race)	C++14	컴파일 오류	0 ms	0 KB

race

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#include<bits/stdc++.h>
using namespace std;

#define fi first
#define int long long
#define bit(i, j) (i >> j & 1)
#define all(x) (x).begin(),(x).end()
#define se second
#define sz(x) (int)(x).size()
#define pb push_back

const int MAXN = 2e5 + 5;
const int INF = 1e18;

int n, k, ans = INF;
int sz[MAXN], minroad[1000001];
bool del[MAXN];
vector<pair<int, int>> adj[MAXN];

void getsize(int u, int p) {
    sz[u] = 1;
    for (pair<int, int> v : adj[u]) {
        if (v.fi != p && !del[v.fi]) {
            getsize(v.fi, u);
            sz[u] += sz[v.fi];
        }
    }
}

int centroid(int u, int p, int tsize) {
    for (auto v : adj[u]) {
        if (v.fi != p && !del[v.fi] && sz[v.fi] * 2 > tsize) {
            return centroid(v.fi, u, tsize);
        }
    }
    return u;
}

void dfs(int u, int p, int cost, int road) {
    if (cost > k) return;
    ans = min(ans, road + minroad[k - cost]);
    for (auto v : adj[u]) {
        if (v.fi != p && !del[v.fi]) {
            dfs(v.fi, u, cost + v.se, road + 1);
        }
    }
}

void add(int u, int p, int cost, int road) {
    if (cost > k) return;
    minroad[cost] = min(minroad[cost], road);
    for (auto v : adj[u]) {
        if (v.fi != p && !del[v.fi]) {
            add(v.fi, u, cost + v.se, road + 1);
        }
    } 
}

void decompose(int u) {
    getsize(u, u);
    int ct = centroid(u, u, sz[u]);
    for (auto v : adj[ct]) {
        if (!del[v.fi]) {
            dfs(v.fi, ct, v.se, 1);
            add(v.fi, ct, v.se, 1);
        }
    }
    del[ct] = 1;
    for (pair<int, int> v : adj[ct]) {
        if (!del[v.fi]) decompose(v.fi);
    }
}

void solve() {
    cin >> n >> k;
    for (int i = 1; i < n; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].pb({v, w});
        adj[v].pb({u, w});
    }
    for (int i = 1; i <= 1000000; ++i) minroad[i] = INF;
    decompose(1);
    if (ans == INF) cout << -1;
    else cout << ans;
}

int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int tt = 1; // cin >> tt;
    while (tt--) solve();
    cerr << "\nTime elapsed: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
    return 0;
}

Compilation message

/usr/bin/ld: /tmp/ccnwZEB9.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc1tfTea.o:grader.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/cc1tfTea.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