Submission #633474

#	Time	Username	Problem	Language	Result	Execution time	Memory
633474		LeonaRaging	Race (IOI11_race)	C++14	Compilation error	0 ms	0 KiB

race

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

#define fi first
#define se second
#define ll long long
#define pb push_back
#define db(val) "[" #val " = " << (val) << "] "

const ll mod = 1e9 + 7;
const int maxn = 2e5 + 4;
const int INF = 1e9;

int n, k, res;
set<pair<int,int>> adj[maxn];
map<ll,int> L, cur;

void dfs(int u, int p, ll dis, int len) {
    if (dis > k) return;
    cur[dis] = len;
    auto it = L.find(k - dis);
    if (it != L.end())
        res = min(res, len + it->se);
    for (auto it : adj[u]) {
        int v; ll w; tie(v, w) = it;
        if (v == p) continue;
        dfs(v, u, dis + w, len + 1);
    }
}

void Solve(int u) {
    L.clear();
    L[0] = 0;
    for (auto it : adj[u]) {
        int v; ll w; tie(v, w) = it;
        cur.clear();
        dfs(v, u, w, 1);
        for (auto it : cur) {
            if (L.find(it.fi) == L.end()) L[it.fi] = it.se;
            else L[it.fi] = min(L[it.fi], it.se);
        }
    }
}

struct CentroidDecomposition {
    int sz[maxn];
    int dfs(int u, int p) {
        sz[u] = 1;
        for (auto it : adj[u])
            if (it.fi != p) sz[u] += dfs(it.fi, u);
        return sz[u];
    }
    int Centroid(int u, int p, int tot) {
        for (auto it : adj[u])
            if (it.fi != p && sz[it.fi] > tot / 2)
                return Centroid(it.fi, u, tot);
        return u;
    }
    void build(int u) {
        int tot = dfs(u, 0);
        int c = Centroid(u, 0, tot);
        Solve(c);
        vector<pair<int,int>> del(adj[c].begin(), adj[c].end());
        for (auto it : del) {
            int v, w; tie(v, w) = it;
            adj[c].erase(it);
            adj[v].erase(adj[v].find({c, w}));
            build(v);
        }
    }
} Cen;

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen(".INP", "r", stdin);
    //freopen(".OUT", "w", stdout);
    cin >> n >> k;
    for (int i = 1; i < n; i++) {
        int u, v, w; cin >> u >> v >> w;
        u++, v++;
        adj[u].insert({v, w});
        adj[v].insert({u, w});
    }
    res = INF;
    Cen.build(1);
    cout << (res == INF ? -1 : res);
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccwt9Mtk.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccXxUfrn.o:grader.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccXxUfrn.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