Submission #1286522

#	Time	Username	Problem	Language	Result	Execution time	Memory
1286522		harryleee	Race (IOI11_race)	C++20	Compilation error	0 ms	0 KiB

race

#include<bits/stdc++.h>
using namespace std;
const int maxn = 2e5;
int n, k, ans = 1e9, len[maxn], cnt[maxn];
pair<int, int> road[maxn];
vector<pair<int, int>> adj[maxn];
bool del[maxn];

void DFS_cnt(int u, int p){
    cnt[u] = 1;
    for (int i = 0; i < adj[u].size(); ++i){
        int v = adj[u][i].first;
        if (v == p || del[v]) continue;
        DFS_cnt(v, u);
        cnt[u] += cnt[v];
    }
    return;
}

int find_centroid(int u, int p, int n){
    for (int i = 0; i < adj[u].size(); ++i){
        int v = adj[u][i].first;
        if (v == p || del[v]) continue;
        if (cnt[v] > n / 2)
            return find_centroid(v, u, n);
    }
    return u;
}

void DFS_solve(int u, int p, int dis, int highways, vector<pair<int, int>>& vec){
    if (dis > k) return;
    vec.push_back({dis, highways});
    for (int i = 0; i < adj[u].size(); ++i){
        int v = adj[u][i].first, w = adj[u][i].second;
        if (del[v] || v == p) continue;
        DFS_solve(v, u, dis + w, highways + 1, vec);
    }
    return;
}

void solve(int u){
    DFS_cnt(u, -1);
    int centroid = find_centroid(u, -1, cnt[u]);
    del[centroid] = true;

    map<int, int> mp;
    mp[0] = 0;
    for (int i = 0; i < adj[centroid].size(); ++i){
        int v = adj[centroid][i].first, w = adj[centroid][i].second;
        if (del[v]) continue;
        vector<pair<int, int>> vec;
        DFS_solve(v, centroid, w, 1, vec);
        for (int j = 0; j < vec.size(); ++j){
            int dis = vec[j].first, num = vec[j].second;
            if (mp.find(k - dis) != mp.end()){
                ans = min(ans, mp[k - dis] + num);
            }
            if (mp.find(dis) == mp.end())
                mp[dis] = num;
            else mp[dis] = min(mp[dis], num);
        }
    }

    for (int i = 0; i < adj[centroid].size(); ++i){
        int v = adj[centroid][i].first;
        if (!del[v]) solve(v);
    }
    return;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    memset(del, false, sizeof(del));

    cin >> n >> k;
    for (int i = 0; i < n - 1; ++i)
        cin >> road[i].first >> road[i].second;
    for (int i = 0; i < n - 1; ++i)
        cin >> len[i];
    for (int i = 0; i < n - 1; ++i){
        adj[road[i].first].push_back({road[i].second, len[i]});
        adj[road[i].second].push_back({road[i].first, len[i]});
    }
    solve(0);
    if (ans == 1e9) cout << -1;
    else cout << ans;
    return 0;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccohaWRa.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccCrR7tC.o:race.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccohaWRa.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