Submission #527661

#	Time	Username	Problem	Language	Result	Execution time	Memory
527661		zaneyu	Šarenlist (COCI22_sarenlist)	C++14	110 / 110	15 ms	332 KiB

Main

/*input
4 3 3
1 2
2 3
4 2
1 4
1 3
4 3
*/ 
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

//#pragma GCC optimize("unroll-loops,no-stack-protector")
//order_of_key #of elements less than x
// find_by_order kth element
using ll = long long;
using ld = long double;
using pii = pair<ll,ll>;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
#define f first
#define s second
#define pb push_back
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define FILL(n,x) memset(n,x,sizeof(n))
#define ALL(_a) _a.begin(),_a.end()
#define sz(x) (int)x.size()
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define MP make_pair
const ll INF64=4e17;
const int INF=0x3f3f3f3f;
const ll MOD=1e9+7;
const ld PI=acos(-1);
const ld eps=1e-9;
#define lowb(x) x&(-x)
#define MNTO(x,y) x=min(x,(__typeof__(x))y)
#define MXTO(x,y) x=max(x,(__typeof__(x))y)
template<typename T1,typename T2>
ostream& operator<<(ostream& out,pair<T1,T2> P){
    out<<P.f<<' '<<P.s;
    return out;
}
template<typename T>
ostream& operator<<(ostream& out,vector<T> V){
    REP(i,sz(V)) out<<V[i]+1<<((i!=sz(V)-1)?" ":"");
    return out;
}
ll mult(ll a,ll b){
    return ((a%MOD)*(b%MOD))%MOD;
}
ll mypow(ll a,ll b){
    if(b<=0) return 1;
    ll res=1LL;
    while(b){
        if(b&1) res=mult(res,a);
        a=mult(a,a);
        b>>=1;
    }
    return res;
}
const int maxn=1e3+5;
ll msk[maxn],mskk[maxn];
vector<pii> v[maxn];
vector<pii> pth;
int b;
int par[maxn];
int find(int u){
    if(par[u]==u) return u;
    return par[u]=find(par[u]);
}
void merge(int a,int b){
    a=find(a),b=find(b);
    if(a==b) return;
    mskk[b]|=mskk[a];
    par[a]=b;
}
ll dfs(int u,int p){
    if(u==b) return 0;
    for(auto x:v[u]){
        if(x.f==p) continue;
        ll z=dfs(x.f,u);
        if(z!=-1){
            return (z|(1LL<<x.s));
        }
    }
    return -1;
}
int main(){
    int n,m,k;
    cin>>n>>m>>k;
    REP(i,n-1){
        int a,b;
        cin>>a>>b;
        --a,--b;
        v[a].pb({b,i}),v[b].pb({a,i});
    }
    REP(i,m){
        int a;
        cin>>a>>b;
        --a,--b;
        msk[i]=dfs(a,-1);
    }
    int ans=0;
    REP(i,(1<<m)){
        vector<int> vv;
        REP(j,m){
            if(i&(1<<j)){
                vv.pb(j);
            }
        }
        REP(i,m) par[i]=i,mskk[i]=msk[i];
        for(int a:vv){
            for(int b:vv){
                if(a>=b) continue;
                if((msk[a]&msk[b])){
                    merge(a,b);
                }
            }
        }
        int cnt=n-1;
        REP(j,m){
            if(find(j)!=j or !(i&(1<<j))) continue; 
            cnt-=__builtin_popcountll(mskk[j]);
            cnt++;
        }
        int z=mypow(k,cnt);
        if(__builtin_popcount(i)%2) ans+=(MOD-z);
        else ans+=z;
        ans%=MOD;
    }
    cout<<ans<<'\n';
}

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