Submission #893091

#	Time	Username	Problem	Language	Result	Execution time	Memory
893091		alexander707070	Security Guard (JOI23_guard)	C++14	76 / 100	4035 ms	64700 KiB

guard

#include<bits/stdc++.h>
#define MAXN 200007
using namespace std;
 
struct edge{
    int from,to,cost;
};
 
bool cmp(edge fr,edge sc){
    return fr.cost<sc.cost;
}
 
int n,m,q,a,b,s[MAXN],c,d,mins;
vector<edge> w;
unordered_set<int> tree[MAXN];
long long ans;
bool ok;
 
int dsu[MAXN],sz[MAXN],maxs;
 
int root(int x){
    if(dsu[x]==x)return x;
    dsu[x]=root(dsu[x]);
    return dsu[x];
}
 
void mergev(int x,int y){
    int rootx=root(x);
    int rooty=root(y);
 
    if(sz[rooty]>sz[rootx])swap(rootx,rooty);
    sz[rootx]+=sz[rooty];
    dsu[rooty]=dsu[rootx];
}

void dfs(int x,int p,int maxcost,int dx,int dy){
    if(maxcost-s[x]-s[mins]>maxs){
        maxs=maxcost-s[x]-s[mins];
        c=mins; d=x; a=dx; b=dy;
    }

    for(int curr:tree[x]){
        if(curr==p)continue;
        if(s[curr]+s[x]>maxcost){
            dfs(curr,x,s[curr]+s[x],curr,x);
        }else{
            dfs(curr,x,maxcost,dx,dy);
        }
    }
}
 
int main(){
 
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
    cin>>n>>m>>q;

    mins=1;
    for(int i=1;i<=n;i++){
        cin>>s[i];
        ans-=s[i];
        maxs=max(maxs,s[i]);
 
        dsu[i]=i; sz[i]=1;
        if(s[i]<s[mins])mins=i;
    }
 
    for(int i=1;i<=m;i++){
        cin>>a>>b;
        w.push_back({a,b,s[a]+s[b]});
    }
 
    sort(w.begin(),w.end(),cmp);
 
    for(int i=0;i<w.size();i++){
        if(root(w[i].from)==root(w[i].to))continue;
        mergev(w[i].from,w[i].to);
 
        tree[w[i].from].insert(w[i].to);
        tree[w[i].to].insert(w[i].from);
 
        ans+=s[w[i].from]+s[w[i].to];
    }
 
    ans+=maxs;
 
    cout<<ans<<"\n";
 
    for(int i=1;i<=q;i++){
 
        maxs=0;
        if(!ok)dfs(mins,0,0,0,0);
 
        if(maxs!=0){
            ans-=maxs;
            tree[a].erase(b);
            tree[b].erase(a);
 
            tree[c].insert(d);
            tree[d].insert(c);
        }else ok=true;
  
        cout<<ans<<"\n";
    }
 
 
    return 0;
}

Compilation message (stderr)

guard.cpp: In function 'int main()':
guard.cpp:77:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |     for(int i=0;i<w.size();i++){
      |                 ~^~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 13 / 13
• Subtask 5: 8 / 8
• Subtask 6: 18 / 18
• Subtask 7: 0 / 24