Submission #746171

#	Time	Username	Problem	Language	Result	Execution time	Memory
746171		kongum	Race (IOI11_race)	C++17	Compilation error	0 ms	0 KiB

race

#include <bits/stdc++.h>
#define ll long long
#define double long double
#define fi first
#define se second
#define all(a) (a).begin(), (a).end()
using namespace std;
using pii = pair<ll, ll>;
using ti3 = tuple<ll, ll, ll>;
const ll MAX = 200010, INF = (ll) 1e9 + 7;
ll n, k, sz[MAX], cPar[MAX], visited[MAX], ans = INF;
vector<pii> g[MAX];
map<ll, ll> mp;

ll getSize(ll cur, ll p) {
    sz[cur] = 1;
    for (pii nxt: g[cur]) {
        if (nxt.fi != p && !visited[nxt.fi]) sz[cur] += getSize(nxt.fi, cur);
    }
    return sz[cur];
}

ll getCentroid(ll cur, ll p, ll cap) {
    for (pii nxt: g[cur]) {
        if (nxt.fi != p && !visited[nxt.fi] && sz[nxt.fi] * 2 > cap) {
            return getCentroid(nxt.fi, cur, cap);
        }
    }   
    return cur;
}

void dfs(ll cur, ll p, ll length, ll edgeCnt) {
    if (mp.find(k - length) != mp.end()) ans = min(ans, mp[k - length] + edgeCnt);

    if (mp.find(length) == mp.end()) mp.insert({ length, edgeCnt });
    mp[length] = min(mp[length], edgeCnt);

    for (pii nxt: g[cur]) {
        if (nxt.fi != p && !visited[nxt.fi]) {
            dfs(nxt.fi, cur, length + nxt.se, edgeCnt + 1);
        }
    }
}

void buildTree(ll cur, ll p) {
    ll ctr = getCentroid(cur, -1, getSize(cur, -1));
    
    mp.clear(); mp.insert({ 0, 0 });
    dfs(ctr, -1, 0, 0);

    cPar[ctr] = p, visited[ctr] = true;
    for (pii nxt: g[ctr]) {
        if (!visited[nxt.fi]) {
            buildTree(nxt.fi, ctr);
        }
    }
}

int main() {
    ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    ll a, b, w;
    cin >> n >> k;
    for (ll i = 0; i < n; i++) {
        cin >> a >> b >> w;
        g[a].push_back({ b, w }); g[b].push_back({ a, w });
    }

    buildTree(0, -1);
    if (ans == INF) ans = -1;
    cout << ans;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccLFg5Xk.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cclNpyLj.o:grader.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/cclNpyLj.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