Submission #1107713

#	Time	Username	Problem	Language	Result	Execution time	Memory
1107713		HNa_seawjing	Šarenlist (COCI22_sarenlist)	C++14	110 / 110	12 ms	33296 KiB

Main

#include <bits/stdc++.h>
//code
#define fl(i,x,y,z) for(int i=x;i<=y;i=i+z)
#define fn(i,x,y,z) for(int i=x;i>=y;i=i-z)
#define rep(i,x,y) for(int i=x;i<y;i=i+1)
#define all(v) v.begin(),v.end()
#define pb emplace_back
#define tle cout<<"tle"<<endl
#define edl cout<<"\n"
#define el "\n"
#define getbit(x,i) ((x>>i)&1)
#define bitcnt __builtin_popcountll
//ham
#define pii pair<int,int>
#define fi first
#define se second
#define ll long long
#define ld long double
#define inf 0x3f3f3f3f
#define int long long
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int maxn=1e6+5;
const int maxlog=7;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if(x < 0) x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if(x < 0) x += mod;
}
int n,m,k;
int lab[maxn];
int high[maxn],lowest[maxn][9],g[maxn][9],par[maxn];
vector <int> e[maxn];
int pw[maxn];
int ans=0;
void DFS(int u,int par)
{
    for (int v: e[u])
    {
        if (v==par) continue;
        high[v]=high[u]+1;
        lowest[v][0]=u;
        g[v][0]=(1ll<<v);
        fl(j,1,maxlog,1)
        {
            lowest[v][j]=lowest[lowest[v][j-1]][j-1];
            g[v][j]=(g[v][j-1] | g[lowest[v][j-1]][j-1]);
        }
        DFS(v,u);
    }
}
ll lca(int u,int v)
{
    ll ans=0;
    if (high[u]<high[v]) swap(u,v);
    int ebsing=high[u]-high[v];
    fl(i,0,maxlog,1)
        if (getbit(ebsing,i))
        {
            ans|= g[u][i];
            u=lowest[u][i];
        }
    if (u==v) return ans;
    fn(i,maxlog,0,1)
        if (lowest[u][i]!=lowest[v][i])
        {
            ans |= g[u][i];
            ans |= g[v][i];
            u=lowest[u][i];
            v=lowest[v][i];
        }
    ans|=g[u][0];
    ans|=g[v][0];
    return ans;
}
int findset(int u)
{
    if (lab[u]<0) return u;
    else return lab[u]=findset(lab[u]);
}
void joinset(int u,int v)
{
    if (lab[u]>lab[v]) swap(u,v);
    lab[u]+=lab[v];
    lab[v]=u;
}
void inp()
{
    cin>>n>>m>>k;
    rep(i,1,n)
    {
        int u,v; cin>>u>>v;
        e[u].pb(v);
        e[v].pb(u);
    }
    DFS(1,0);
    rep(i,0,m)
    {
        int u,v; cin>>u>>v;
        par[i]=lca(u,v);
    }
}
void sol()
{
    pw[0]=1;
    rep(i,1,n)
        pw[i]=1ll*pw[i-1]*k%mod;
    rep(mask,0,1<<m)
    {
        fl(i,0,m,1) lab[i]=-1;
        vector <int> save;
        ll t=0; int cnt=0;
        rep(i,0,m) if (getbit(mask,i))
        {
            for (int j: save) if (par[i] & par[j])
            {
                int u=findset(i);
                int v=findset(j);
                if (u!=v) joinset(u,v);
            }
            save.pb(i);
            t |= par[i];
        }
        for (int i: save) if (lab[i]<0) cnt++;
        cnt= cnt+n-1-(bitcnt(t));
        if (bitcnt(mask)&1) del(ans,pw[cnt]);
        else add(ans,pw[cnt]);
//        cout<<cnt<< " "<<t<< el;
    }
    cout<<ans;
}
signed main()
{
    #define name "seaw"
    if (fopen(name".inp", "r"))
    {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    inp();sol();
    return 0;
}
/*   /\_/\
    ( ._. )
    / >V< \
*/

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:164:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  164 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:165:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  165 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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