Submission #2072438

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Source Code Expand

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

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;

#define fi first
#define se second
#define repl(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define rep(i,n) repl(i,0,n)
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<x<<endl
#define mmax(x,y) (x>y?x:y)
#define mmin(x,y) (x<y?x:y)
#define maxch(x,y) x=mmax(x,y)
#define minch(x,y) x=mmin(x,y)
#define uni(x) x.erase(unique(all(x)),x.end())
#define exist(x,y) (find(all(x),y)!=x.end())
#define bcnt __builtin_popcount

#define INF 1e16

struct UnionFind{
  vector<int> v;
  UnionFind(int n) : v(n, -1) {}
  void init(){ for(int i = 0;i < v.size();i++)v[i]=-1; }
  int find(int x) { return v[x] < 0 ? x : v[x] = find(v[x]); }
  bool unite(int x, int y) {
    x = find(x); y = find(y);
    if (x == y) return false;
    if (-v[x] < -v[y]) swap(x, y);
    v[x] += v[y]; v[y] = x;
    return true;
  }
  bool root(int x) { return v[x] < 0; }
  bool same(int x, int y) { return find(x) == find(y); }
  int size(int x) { return -v[find(x)]; }
};

struct edge{
  ll f,t,c;
};

bool operator<(const edge& a,const edge& b){return a.c < b.c;}

ll n,m,k;
ll col[101010];
vector<edge> es;

int main(){
	cin>>n>>m>>k;
  rep(i,n){
    cin>>col[i];
    col[i]--;
  }
  ll crtidx=k;
  rep(i,n)if(col[i]==-1)col[i]=crtidx++;
  rep(i,m){
    ll a,b,c;
    cin>>a>>b>>c;
    a--; b--;
    a=col[a];
    b=col[b];
    es.push_back((edge){a,b,c});
  }
  ll res=0,en=0;
  UnionFind uf(crtidx);
  sort(all(es));
  rep(i,m){
    edge e=es[i];
    ll u=e.f,v=e.t;
    if(uf.same(u,v))continue;
    uf.unite(u,v);
    res+=e.c;
    en++;
    if(en>=k-1)break;
  }
  if(en<k-1)cout<<-1<<endl;
  else cout<<res<<endl;

	return 0;
}

Submission Info

Judge Result