Submission #893036

#	Time	Username	Problem	Language	Result	Execution time	Memory
893036		alexander707070	Security Guard (JOI23_guard)	C++14	58 / 100	4009 ms	56848 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;
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];
}

int best(int x,int y){
    if(s[x]<s[y])return x;
    return y;
}

int dfs(int x,int p){
    int res=x;

    for(int e:tree[x]){
        if(e==p)continue;
        res=best(res,dfs(e,x));
    }

    return res;
}

int main(){

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>m>>q;

    for(int i=1;i<=n;i++){
        cin>>s[i];
        ans-=s[i];
        maxs=max(maxs,s[i]);

        dsu[i]=i; sz[i]=1;
    }

    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;

        for(int f=1;f<=n and !ok;f++){
            for(int e:tree[f]){
                if(e<f)continue;

                int sx=dfs(f,e);
                int sy=dfs(e,f);
                
                if(s[f]+s[e]-s[sx]-s[sy]>maxs){
                    maxs=s[f]+s[e]-s[sx]-s[sy];
                    a=f; b=e; c=sx; d=sy;
                }
            }
        }

        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:75:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |     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: 0 / 18
• Subtask 7: 0 / 24