Submission #1185710

#	Time	Username	Problem	Language	Result	Execution time	Memory
1185710		asli_bg	Šarenlist (COCI22_sarenlist)	C++20	10 / 110	0 ms	328 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;

#define int long long

typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<bool> vb;

typedef tree<pii,null_type,less<pii>,rb_tree_tag,
tree_order_statistics_node_update> oset;

#define fi first
#define se second
#define pb push_back

#define mid (l+r)/2
#define all(x) x.begin(),x.end()
#define FOR(i,a) for(int i=0;i<(a);i++)
#define FORE(i,a,b) for(int i=(a);i<(b);i++)

#define cont(x) for(auto el:x) cout<<el<<' ';cout<<endl;
#define contp(x) for(auto el:x) cout<<el.fi<<'-'<<el.se<<' ';cout<<endl;
#define sp <<" "<<

#define DEBUG(x) cout<<(#x) sp x<<endl
#define carp(a,b) (((a%MOD)*(b%MOD))%MOD)
#define topla(a,b) (((a%MOD)+(b%MOD))%MOD)

const int INF=1e18;
const int MAXN=65;
const int MAXK=10;
const int MOD=1e9+7;

int n,m,k;

vi adj[MAXN];
int up[MAXN][MAXK];

int dep[MAXN], p[MAXN];

void dfs(int nd,int ata,int h){
    dep[nd]=h;
    p[nd]=ata;
    for(auto kom:adj[nd]){
        if(kom==ata) continue;
        dfs(kom,nd,h+1);
    }
}

void calc(){
    memset(up,-1,sizeof up);
    FORE(i,1,n+1){
        up[i][0]=p[i];
    }

    FORE(j,1,MAXK){
        FORE(i,1,n+1){
            if(up[i][j-1]==-1) continue;
            up[i][j]=up[up[i][j-1]][j-1];
        }
    }
}

int lca(int a,int b){
    //a altta olan, b üstte olan
    if(dep[a]<dep[b]) swap(a,b);
    for(int i=MAXK-1;i>=0;i--){
        int tt=up[a][i];
        if(tt==-1) continue;
        if(dep[tt]>=dep[b]) a=tt;
    }

    if(a==b) return a;

    for(int i=MAXK-1;i>=0;i--){
        int bir=up[a][i];
        int iki=up[b][i];

        if(bir==-1 or iki==-1) continue;
        if(bir!=iki){
            a=bir;
            b=iki;
        }
    }

    return up[a][0];
}

int exp(int x,int us){
    int res=1;
    while(us>0){
        if(us&1) res=carp(res,x);
        x=carp(x,x);
        us/=2;
    }
    return res;
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>m>>k;

    FOR(i,n-1){
        int a,b;
        cin>>a>>b;
        adj[a].pb(b);
        adj[b].pb(a);
    }

    dfs(1,-1,0);

    calc();

    while(m--){
        int a,b;
        cin>>a>>b;
        int ata=lca(a,b);

        int dd=dep[a]+dep[b]-2*dep[ata];
        int kalan=n-1-dd;

        cout<<carp(exp(k,kalan),topla(exp(k,dd),MOD-k))<<endl;
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 65