Submission #1271412

#	Time	Username	Problem	Language	Result	Execution time	Memory
1271412		trandangquang	Construction of Highway (JOI18_construction)	C++20	100 / 100	196 ms	17352 KiB

construction

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

#define foru(i,a,b) for(int i=(a); i<=(b); ++i)
#define ford(i,a,b) for(int i=(a); i>=(b); --i)
#define rep(i,a) for(int i=0; i<(a); ++i)
#define sz(a) (int)(a).size()
#define all(a) (a).begin(),(a).end()
#define bit(s,i) (((s)>>(i))&1)
#define ii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define ll long long

template <class X, class Y> bool maxi(X &x, Y y){return x<y?x=y,true:false;}
template <class X, class Y> bool mini(X &x, Y y){return x>y?x=y,true:false;}

const int N=1e5+5;

int n,c[N],a[N],b[N];
int sz[N],par[N],head[N],idCh[N],curCh,h[N];
vector<int> adj[N];
vector<int> rar;
vector<ii> sigma[N];

void pre(int u){
    sz[u]=1;
    for(int v:adj[u]){
        par[v]=u;
        h[v]=h[u]+1;
        pre(v);
        sz[u]+=sz[v];
    }
}

void hld(int u){
    if(!head[curCh]){
        head[curCh]=u;
        sigma[curCh].eb(0,0);
    }
    idCh[u]=curCh;
    sigma[idCh[u]].back().se++;

    int bigCh=-1;
    for(int v:adj[u]){
        if(bigCh==-1 || sz[bigCh]<sz[v]) bigCh=v;
    }

    if(bigCh!=-1) hld(bigCh);
    for(int v:adj[u]) if(v!=bigCh){
        ++curCh;
        hld(v);
    }
}

void upd(int x, int val){
    while(x!=0){
        int szNeed=h[x]-h[head[idCh[x]]]+1, tmp=szNeed;
        while(szNeed>0){
            if(sigma[idCh[x]].back().se<=szNeed){
                szNeed-=sigma[idCh[x]].back().se;
                sigma[idCh[x]].pop_back();
            } else{
                sigma[idCh[x]].back().se-=szNeed;
                szNeed=0;
            }
        }
        sigma[idCh[x]].eb(val,tmp);
        x=par[head[idCh[x]]];
    }
}

int fw[N];
void updf(int id, int val){
    for(; id<=n; id+=id&-id) fw[id]+=val;
}
int getf(int id){
    int res=0;
    for(; id>0; id-=id&-id) res+=fw[id];
    return res;
}

ll calc(int x){
    ll res=0;
    vector<ii> hi;

    while(x!=0){
        int szNeed=h[x]-h[head[idCh[x]]]+1;

        vector<ii> tmp;
        ford(i,sz(sigma[idCh[x]])-1,0){
            if(szNeed==0) break;
            if(sigma[idCh[x]][i].se<=szNeed){
                tmp.eb(sigma[idCh[x]][i]);
                szNeed-=sigma[idCh[x]][i].se;
            } else{
                tmp.eb(sigma[idCh[x]][i].fi, szNeed);
                szNeed=0;
            }
        }

        reverse(all(tmp));
        for(auto [col,num]:tmp){
//            cout<<col<<" "<<num<<'\n';
            res+=1LL*num*getf(col-1);
            updf(col,num);
            hi.eb(col,num);
        }
        x=par[head[idCh[x]]];
    }
//    cout<<'\n';
    for(auto [col,num]:hi) updf(col,-num);
    return res;
}

void solve(){
    cin>>n;
    foru(i,1,n) cin>>c[i];

    /// compress
    foru(i,1,n) rar.eb(c[i]);
    sort(all(rar));
    rar.erase(unique(all(rar)),rar.end());
    foru(i,1,n) c[i]=lower_bound(all(rar),c[i])-rar.begin()+1;

    /// build hld
    foru(i,1,n-1){
        cin>>a[i]>>b[i];
        adj[a[i]].eb(b[i]);
    }
    pre(1);
    hld(1);

    /// process

    upd(1,c[1]);
    foru(i,1,n-1){
        cout<<calc(a[i])<<'\n';
        upd(b[i],c[b[i]]);
    }
}

int32_t main(){
    #define task "test"
    if(fopen(task".inp","r")){
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    cin.tie(0)->sync_with_stdio(0);

    int tc=1; //cin>>tc;
    rep(_,tc){
        solve();
    }
}

Compilation message (stderr)

construction.cpp: In function 'int32_t main()':
construction.cpp:148:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  148 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
construction.cpp:149:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  149 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 84 / 84