Submission #556258

#	Time	Username	Problem	Language	Result	Execution time	Memory
556258		new_acc	Šarenlist (COCI22_sarenlist)	C++14	110 / 110	27 ms	348 KiB

Main

#include<bits/stdc++.h>
#define fi first
#define se second
#define pitem item*
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vl;
const int N=100;
const int M=16;
const int SS=1<<19;
const int INFi=2e9;
const ll INFl=1e13;
const ll mod2=998244353;
const ll mod=1e9+7;
const ll mod3=1000696969;
const ll p=70032301;
const ull p2=913;
const int L=20;
int dp[(1<<M)+10],fau[N],dep[N],val[N],oj[N];
ll pot[N];
vector<pair<int,int> >graf[N];
bitset<N>vis;
pair<int,int> w[N];
int Find(int a){
    if(fau[a]==a) return a;
    return fau[a]=Find(fau[a]);
}
void Union(int a,int b){
    fau[Find(a)]=Find(fau[b]);
}
void dfs(int v,int o){
    for(auto [u,id]:graf[v]){
        if(u==o) continue;
        oj[u]=v,val[u]=id;
        dep[u]=dep[v]+1;
        dfs(u,v);
    }
}
void solve(){
    int n,m;
    ll k;
    cin>>n>>m>>k;
    pot[0]=1;
    for(int i=1;i<=n;i++) pot[i]=(pot[i-1]*k)%mod;
    for(int a,b,i=1;i<n;i++){
        cin>>a>>b;
        graf[a].push_back({b,i}),graf[b].push_back({a,i});
    }
    dfs(1,1);
    for(int i=1;i<=m;i++) cin>>w[i].fi>>w[i].se;
    ll res=pot[n-1];
    for(int i=1;i<(1<<m);i++){
        for(int i=1;i<n;i++) fau[i]=i;
        for(int j=0;j<m;j++){
            if((1<<j)&i){
                int a=w[j+1].fi,b=w[j+1].se,pop=0;
                while(a!=b){
                    if(dep[a]<dep[b]) swap(a,b);
                    if(pop!=0) Union(pop,val[a]);
                    else pop=val[a];
                    a=oj[a];
                }
            }
        }
        vis.reset();
        int curr=0;
        for(int j=1;j<n;j++){
            if(!vis[Find(j)]){
                curr++; 
                vis[Find(j)]=1;
            }
        }
        ll akt=pot[curr]*(__builtin_popcount(i)&1?-1:1);
        (res+=akt+mod)%=mod;
    }
    cout<<res<<"\n";
}
int main(){
    ios_base::sync_with_stdio(0),cin.tie(0);
    int tt=1;
    while(tt--) solve();
}

Compilation message (stderr)

Main.cpp: In function 'void dfs(int, int)':
Main.cpp:34:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   34 |     for(auto [u,id]:graf[v]){
      |              ^

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 65 / 65