Submission #1116826

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116826		0pt1mus23	Paths (BOI18_paths)	C++14	23 / 100	3080 ms	25096 KiB

paths

// #pragma GCC optimize("Ofast,unroll-loops")

// el psy congroo
#include <bits/stdc++.h>
using namespace std;
#define int long long int
#define ins insert      
#define pii pair<int,int>
#define pb push_back
#define endl '\n'
#define putr(x) cout<<x<<endl;return; 
#define all(x) x.begin(),x.end()
const int mod = 1e9 +7, sze = 3e5+23, inf = INT_MAX, LG = 19,pr = 31;
vector<int> graph[sze];
map<int,int> var;
vector<int> ord;
int col[sze];
int dp[sze];
int nxt[sze];

void dfs(int node,int idx){
    if(idx== (ord.size()-1 ) ){
        dp[node]=1;
        return;
    }
    for(auto v:graph[node]){
        if(col[v]==ord[idx+1]){
            dp[v]=0;
            dfs(v,idx+1);
            dp[node]+=dp[v];
        }
    }
}
vector<int> cc[10];

void fast(){
    int n,m,k;
    cin>>n>>m>>k;
    for(int i =1;i<=n;i++){
        cin>>col[i];
        cc[col[i]].pb(i);
    }
    int u,v;
    for(int i =0;i<m;i++){
        cin>>u>>v;
        graph[u].pb(v);
        graph[v].pb(u);
    }

    int ans=0;
    vector<int> ad;
    for(int i =0;i<k;i++){
        ad.pb(i+1);
    }
    int hash=0,pp;
    // for(auto v:ad) cout<<v<<" ";cout<<endl;
    do{
        hash=ad[0],pp=1;
        ord.clear();
        ord.pb(ad[0]);
        for(int i =1;i<k;i++){
            pp = (pp* pr)%mod;
            hash=(hash + ad[i] * pp  % mod) %mod;
            ord.pb(ad[i]);
            if(!var[hash]){
                // for(auto v:ord) cout<<v<<" ,";cout<<endl;
                for(int j=1;j<=n;j++){
                    dp[j]=0;    
                }
                for(auto v:cc[ord[0]]){

                    dfs(v,0);
                    if(dp[v]){
                        // cout<<v<<" == "<<dp[v]<<endl;
                        ans=(ans+dp[v])%mod;
                    }
                }
                var[hash]=1;
            }
        }
    }while(next_permutation(all(ad)));
    putr(ans);
}
 
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
    int tt = 1;
    // cin>>tt;
 
    while(tt--){
        fast();
    }
    return 0;
}

Compilation message (stderr)

paths.cpp: In function 'void dfs(long long int, long long int)':
paths.cpp:22:11: 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]
   22 |     if(idx== (ord.size()-1 ) ){
      |        ~~~^~~~~~~~~~~~~~~~~~

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