Submission #655583

#	Time	Username	Problem	Language	Result	Execution time	Memory
655583		urosk	Swapping Cities (APIO20_swap)	C++14	7 / 100	386 ms	68100 KiB

swap

#define here cerr<<"===========================================\n"
#define dbg(x) cerr<<#x<<": "<<x<<endl;
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#define ld double
#define ll int
#define llinf 100000000000000000LL // 10^17
#define pb push_back
#define popb pop_back
#define fi first
#define sc second
#define endl '\n'
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define sz(a) (ll)(a.size())
#define all(a) a.begin(),a.end()
#define ceri(a,l,r) {cerr<<#a<<": ";for(ll i_ = l;i_<=r;i_++) cerr<<a[i_]<< " ";cerr<<endl;}
#define cer(a) {cerr<<#a<<": ";for(ll x_ : a) cerr<<x_<< " ";cerr<<endl;}

#define daj_mi_malo_vremena ios_base::sync_with_stdio(false);cerr.tie(0);cout.tie(0);cin.tie(0);

using namespace std;

#define maxn 500005
#define lg 21
ll n,m;
vector<ll> g[maxn];
struct gr{
    ll x,y,w;
};
bool cmp(gr a,gr b){return a.w<b.w;}
vector<gr> edge;
ll c[maxn];
bool ok[maxn];
ll dsu[maxn];
ll deg[maxn];
ll in[maxn];
ll out[maxn];
ll it;
ll root(ll x){
    while(x!=dsu[x]){
        dsu[x] = dsu[dsu[x]];
        x = dsu[x];
    }
    return x;
}
ll st[maxn][lg];
ll oke[maxn][lg];
vector<pll> v;
void upd(ll x,ll y,ll w){
    deg[x]++; deg[y]++;
    bool f = (deg[x]>=3)||(deg[y]>=3);
    x = root(x); y = root(y);
    ++it;
    if(x==y){
        g[x].pb(it);
        g[it].pb(x);
        v.pb({it,x});
        ok[it] = 1;
        dsu[x] = it;
    }else{
        g[x].pb(it);
        g[it].pb(x);
        g[y].pb(it);
        g[it].pb(y);
        v.pb({it,x});
        v.pb({it,y});
        ok[it] = ok[x]|ok[y]|f;
        dsu[x] = dsu[y] = it;
    }
    c[it] = w;
}
ll itr = 0;
void dfs(ll u,ll p){
    st[u][0] = p;
    oke[u][0] = ok[p];
    in[u] = ++itr;
    for(ll s : g[u]){
        if(s==p) continue;
        dfs(s,u);
    }
    out[u] = itr;
}
bool intree(ll x,ll y){
    return in[y]<=in[x]&&out[x]<=out[y];
}
ll lca(ll x,ll y){
    if(intree(y,x)) return x;
    if(intree(x,y)) return y;
    for(ll j = lg-1;j>=0;j--){
        if(!intree(x,st[y][j])) y = st[y][j];
    }
    return st[y][0];
}
void init(int N, int M, vector<int> U, vector<int> V, vector<int> W) {
    n = N; m = M;
    it = n;
    iota(dsu+1,dsu+maxn,1);
    for(ll i = 0;i<m;i++){
        ll x = U[i]; ll y = V[i]; ll w = W[i];
        ++x; ++y;
        edge.pb({x,y,w});
    }
    sort(all(edge),cmp);
    for(gr e : edge){
        ll x = e.x; ll y = e.y; ll w = e.w;
        upd(x,y,w);
    }
    dfs(it,it);
    for(ll j = 1;j<lg;j++){
        for(ll i = 1;i<=it;i++) st[i][j] = st[st[i][j-1]][j-1];
    }
    for(ll j = 1;j<lg;j++){
        for(ll i = 1;i<=it;i++) oke[i][j] = oke[i][j-1]|oke[st[st[i][j-1]][0]][j-1];
    }
}
int getMinimumFuelCapacity(int X, int Y) {
    ll x = X; ll y = Y;
    ++x; ++y;
    ll z = lca(x,y);
    if(ok[z]) return c[z];
    for(ll j = lg-1;j>=0;j--){
        if(!oke[z][j]) z = st[z][j];
    }
    z = st[z][0];
    ll ans = c[z];
    if(ok[z]==0) ans = -1;
    return ans;
}
/*
5 6
0 1 4
0 2 4
1 2 1
1 3 2
1 4 10
2 3 3
3
1 2
2 4
0 1
*/

• Subtask 1: 0 / 6
• Subtask 2: 7 / 7
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27