Submission #473372

#	Time	Username	Problem	Language	Result	Execution time	Memory
473372		ZaZo_	Paths (BOI18_paths)	C++14	0 / 100	96 ms	21584 KiB

paths

#include <bits/stdc++.h>
#define ZAZO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define int long long
using namespace std;
int n , m , k;
int cols[300001],another[300001][6]={0};
vector<int>edges[300001];
set<vector<int>>ans;
void dfs(int node,set<int>path,vector<int>path2,int par)
{
  if(path2.size()==0){
  path2.push_back(node);
  path.insert(cols[node]);
  }
  for(int i = 0 ; i < edges[node].size() ; i++)
  {
    if(edges[node][i]!=par && !path.count(cols[edges[node][i]]) && path.size()<=k ){
      path.insert(cols[edges[node][i]]);
      path2.push_back(edges[node][i]);
      ans.insert(path2);
      dfs(edges[node][i] , path , path2 , node);
      path2.erase(path2.begin()+(path2.size()-1));
      path.erase(cols[edges[node][i]]);
    }
  }
}
int32_t main() {
  ZAZO
  int an2=0;
  cin >> n >> m >> k ;
  vector<pair<int,int>>e;
  for(int i = 1 ; i <= n ; i++)
  {
    cin>>cols[i];
  }
  for(int i = 0 ; i < m ; i++)
  {
    int u , v;
    cin >> u >> v;
    e.push_back({u,v});
    if(cols[u]!=cols[v]) an2+=2;
    edges[u].push_back(v);
    edges[v].push_back(u);
    another[u][cols[v]]++;
    another[v][cols[u]]++;
  }
  if(n>=100 && m<=100 && k<=4)
  {
    //ba7sb kol path w dah bya5od time 3aly f 7ygeeb awel subtask
    for(int i = 1 ; i <= n ; i++)
    {
      dfs(i,{},{},-1);
    }
    cout<<ans.size()<<endl;
  }
  else
  {
    //subtask 2
    //k<=3 that's mean that maximum path = 3
    if(k==1){
      cout<<n;
      return 0;
    }
    if(k==2){
      cout<<an2;
      return 0;
    }
    int ans2=m*2;
    for(int o=0;o<e.size();o++)
    {
      int i = e[o].first , j=e[o].second;
      for(int p = 1 ;  p <= k ; p ++)
      {
        if(p!=cols[i]&&p!=cols[j]&&cols[i]!=cols[j]&&i!=j)
        {
        //  cout<<i<< " "<<j<<" "<<p<<" "<<another[i][p]+another[j][p]<<endl;
          ans2+=another[i][p]+another[j][p];
        }
      }
    }

    cout<<ans2<<endl;
  }
}

Compilation message (stderr)

paths.cpp: In function 'void dfs(long long int, std::set<long long int>, std::vector<long long int>, long long int)':
paths.cpp:15:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |   for(int i = 0 ; i < edges[node].size() ; i++)
      |                   ~~^~~~~~~~~~~~~~~~~~~~
paths.cpp:17:79: warning: comparison of integer expressions of different signedness: 'std::set<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   17 |     if(edges[node][i]!=par && !path.count(cols[edges[node][i]]) && path.size()<=k ){
      |                                                                    ~~~~~~~~~~~^~~
paths.cpp: In function 'int32_t main()':
paths.cpp:69:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |     for(int o=0;o<e.size();o++)
      |                 ~^~~~~~~~~

• Subtask 1: 0 / 23
• Subtask 2: 0 / 20
• Subtask 3: 0 / 27
• Subtask 4: 0 / 30