Submission #1261985

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261985		hiepsimauhong	Race (IOI11_race)	C++20	Compilation error	0 ms	0 KiB

race

#include "race.h"
#include <bits/stdc++.h>

using namespace std;
using ll = long long;
#define int long long

const int oo = 1e9;

#define quickly ios_base::sync_with_stdio(0);cin.tie(0); cout.tie(0);
#define print(a,l,r) for(int OK(l); OK <= r ; ++OK){ if(a[OK] < oo){cout << a[OK] <<' ';} else{cout << "- ";}} cout << '\n';
#define prints(a) for(auto i : a){ cout << i <<' ';} cout << '\n';
#define printz(a,l,r) for(int OK(1) ; OK <= l ; ++OK){for(int KO(1) ; KO <= r ; ++KO){if(a[OK][KO] < oo){cout << a[OK][KO] <<' ';}else{cout << "- ";}}cout << '\n';} cout << '\n';
#define fs first
#define sd second
#define ii pair<int, int>
#define iii pair<int, ii>
#define all(a) a.begin(), a.end()

const int N = 2e5 + 5;
const int mod = 1e9 + 7;
const int MAX_HIGH = 1e6 + 5;

int n, k;
vector<ii> a[N];
int in = 0, minx = oo;
int high[N], best[MAX_HIGH], th[MAX_HIGH];

struct Centroid_decomposition{
      int cen[N], sz[N];
      int len[N];

      void DFS_SZ(int u, int par){
            sz[u] = 1;
            for(ii e : a[u]){
                  int v = e.fs, w = e.sd;
                  if(v == par || cen[v]){
                        continue;
                  }
                  DFS_SZ(v, u);
                  sz[u] += sz[v];
            }
      }

      void DFS_ANS(int u, int par, bool ok){
            if(high[u] > k){
                  return;
            }
            if(!ok){
                  if(th[high[u]] != in){
                        th[high[u]] = in;
                        best[high[u]] = len[u];
                  }
                  else{
                        best[high[u]] = min(best[high[u]], len[u]);
                  }
            }
            else{
                  if(th[k - high[u]] == in){
                        minx = min(minx, best[k - high[u]] + len[u]);
                  }
            }

            for(ii e : a[u]){
                  int v = e.fs, c = e.sd;
                  if(v == par || cen[v]){
                        continue;
                  }
                  high[v] = high[u] + c;
                  len[v] = len[u] + 1;
                  DFS_ANS(v, u, ok);
            }
      }

      int find_centroid(int u, int par, int mx){
            for(ii e : a[u]){
                  int v = e.fs;
                  if(v == par || cen[v]){
                        continue;
                  }
                  if(sz[v]  > mx / 2){
                        return find_centroid(v, u, mx);
                  }
            }
            return u;
      }

      void tree(int u){
            DFS_SZ(u, 0);
            int centroid = find_centroid(u, 0, sz[u]);

            cen[centroid] = true;
            ++in;

            len[centroid] = best[0] = high[centroid] = 0;
            th[0] = in;

            for(ii e : a[centroid]){
                  int v = e.fs, w = e.sd;
                  if(cen[v]){
                        continue;
                  }
                  high[v] = w;
                  len[v] = 1;
                  DFS_ANS(v, centroid, 1);
                  DFS_ANS(v, centroid, 0);
            }

            for(ii e : a[centroid]){
                  int v = e.fs;
                  if(!cen[v]){
                        tree(v);
                  }
            }
      }
};

Centroid_decomposition cen;

int best_path(int _N, int _K, int H[][2], int L[]){
      n = _N;
      k = _K;

      for(int i(0) ; i < n - 1 ; ++i){
            int u, v, w;
            u = H[i][0], v = H[i][1], w = L[i];
            a[u + 1].push_back({v + 1, w});
            a[v + 1].push_back({u + 1, w});
      }

      cen.tree(1);

      if(minx == oo){
          return -1;
      }
      return minx;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccgUE8fe.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