Submission #256003

#	Time	Username	Problem	Language	Result	Execution time	Memory
256003		mehrdad_sohrabi	Bridges (APIO19_bridges)	C++14	73 / 100	3080 ms	6924 KiB

bridges

#include <bits/stdc++.h>
typedef int ll;
typedef long double ld;
#define pb push_back
#define pii pair < int , int >
#define F first
#define S second
#define endl '\n'
//#define int long long
#define sync ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#pragma GCC optimize("Ofast,unroll-loops")
#define kill(x) return cout<<x<<'\n', 0;
using namespace std;
const int N=5e4+2,sq=750;
struct IO_Tp{
 bool is_digit(const char ch){
  return '0' <= ch && ch <= '9';
 }
 IO_Tp& operator>>(int& res){
  res = 0;
  static char ch;
  while (ch = getchar(), !is_digit(ch));
  do
   (res *= 10) += ch & 15;
  while (ch = getchar(), is_digit(ch));
  return *this;
 }
} IO;

vector <pair <int,pii > > yy,yal;
bitset<N*2> vis,vis2;
ll nxt[N*2],pre[N*2];
ll par[N],sz[N];
ll getpar(ll v){
    if (par[v]==v) return v;
    return par[v]=getpar(par[v]);
}
inline void mrg(ll v,ll u){
    ll u1=getpar(u),v1=getpar(v);
    if (u1==v1) return ;
    if (sz[u1]>sz[v1])swap(u1,v1);
    par[u1]=v1;
    sz[v1]+=sz[u1];
}
ll pp[N],zz[N];
ll gg(ll v){
    if (pp[v]==v) return v;
    return pp[v]=gg(pp[v]);
}
inline void merg(ll v,ll u){
    ll v1=gg(v),u1=gg(u);
    if (v1==u1) return ;
    if (zz[u1]>zz[v1]) swap(v1,u1);
    pp[u1]=v1;
    zz[v1]+=zz[u1];
}
ll ans[N*2];
vector <pair <int,pii> > q;
int main(){
    sync;
    ll n,m;
  IO >> n >> m;
    for (int i=1;i<=m;i++){
        ll u,v,w;
        IO >> u >> v >> w;
        yy.pb({w,{u,v}});
    }
    ll q1;
    IO >> q1;
    while(q1--){
        ll u,v,w;
        IO >> u >> v >> w;
        u--;
        q.pb({u,{v,w}});
    }
    pre[0]=-1;
    nxt[q.size()-1]=5e6;
    for (int j=1;j<q.size();j++){
        if (!q[j-1].F) pre[j]=j-1;
        else pre[j]=pre[j-1];
    }
    for (int j=(ll)q.size()-2;j>-1;j--){
        if (!q[j+1].F) nxt[j]=j+1;
        else nxt[j]=nxt[j+1];
    }
    for (int i=0;i<q.size();i+=sq){
        vector <pii> g;
        for (int j=i;j<min(i+sq,(int)q.size());j++){
            if (!q[j].F) vis[q[j].S.F-1]=1;
            else{
                g.pb({q[j].S.S,j});
            }
        }
        memset(par,0,sizeof par);
        memset(sz,0,sizeof sz);
        for (int j=1;j<=n;j++){
            sz[j]=1;
            par[j]=j;
        }
        yal.clear();
        for (int j=0;j<yy.size();j++){
            if (!vis[j])
            yal.pb(yy[j]);
        }
        sort(yal.begin(),yal.end());
        sort(g.begin(),g.end());
        reverse(g.begin(),g.end());
        ll cnt=0;
        for (int j=yal.size()-1;j>-1;j--){
            while(cnt<g.size() && g[cnt].F>yal[j].F){
                for (int k=i;k<min(i+sq,(ll)q.size());k++){
                    if (!q[k].F){
                        vis2[q[k].S.F-1]=0;
                        ll v=yy[q[k].S.F-1].S.F,u=yy[q[k].S.F-1].S.S;
                        pp[v]=getpar(v);
                        pp[u]=getpar(u);
                        zz[pp[v]]=sz[pp[v]];
                        zz[pp[u]]=sz[pp[u]];
                        pp[pp[v]]=pp[v];
                        pp[pp[u]]=pp[u];
                    }
                    else{
                        ll v=q[k].S.F;
                        pp[v]=getpar(v);
                        zz[pp[v]]=sz[pp[v]];
                        pp[pp[v]]=pp[v];
                    }
                }
                ll id=g[cnt].S;
                for (int k=id;k>=i;k--){
                    if (q[k].F){
                 //       cout << k << " " << pre[k] << endl;
                        k=pre[k]+1;
                        continue;
                    }
                    ll v=yy[q[k].S.F-1].S.F,u=yy[q[k].S.F-1].S.S;
                    if (vis2[q[k].S.F-1]){
                        k=pre[k]+1;
                        continue;
                    }
                    vis2[q[k].S.F-1]=1;
                    if (q[k].S.S>=g[cnt].F){
                        merg(u,v);
                    }
                    k=pre[k]+1;
                }
                for (int k=id+1;k<min(i+sq,(ll)q.size());k++){
                    if (q[k].F){
                        k=nxt[k]-1;
                        continue;
                    }
                    ll v=yy[q[k].S.F-1].S.F,u=yy[q[k].S.F-1].S.S;
                    if (vis2[q[k].S.F-1]){
                        k=nxt[k]-1;
                        continue;
                    }
                    vis2[q[k].S.F-1]=1;
                    if (yy[q[k].S.F-1].F>=g[cnt].F){
                        merg(u,v);
                    }
                    k=nxt[k]-1;
                }
                ans[id]=zz[gg(q[id].S.F)];
                cnt++;
            }
            mrg(yal[j].S.F,yal[j].S.S);
        }
        while(cnt<g.size()){
                for (int k=i;k<min(i+sq,(ll)q.size());k++){
                    if (!q[k].F){
                        vis2[q[k].S.F-1]=0;
                        ll v=yy[q[k].S.F-1].S.F,u=yy[q[k].S.F-1].S.S;
                        pp[v]=getpar(v);
                        pp[u]=getpar(u);
                        zz[pp[v]]=sz[pp[v]];
                        zz[pp[u]]=sz[pp[u]];
                        pp[pp[u]]=pp[u];
                        pp[pp[v]]=pp[v];
                    }
                    else{
                        ll v=q[k].S.F;
                        pp[v]=getpar(v);
                        zz[pp[v]]=sz[pp[v]];
                        pp[pp[v]]=pp[v];
                    }
                }
                ll id=g[cnt].S;
                for (int k=id;k>=i;k--){
                    if (q[k].F){
                        k=pre[k]+1;
                        continue;
                    }
                    ll v=yy[q[k].S.F-1].S.F,u=yy[q[k].S.F-1].S.S;
                    if (vis2[q[k].S.F-1]){
                        k=pre[k]+1;
                        continue;
                    }
                    vis2[q[k].S.F-1]=1;
                    if (q[k].S.S>=g[cnt].F){
                        merg(u,v);
                    }
                    k=pre[k]+1;
                }
                for (int k=id+1;k<min(i+sq,(ll)q.size());k++){
                    if (q[k].F) {
                        k=nxt[k]-1;
                        continue;
                    }
                    ll v=yy[q[k].S.F-1].S.F,u=yy[q[k].S.F-1].S.S;
                    if (vis2[q[k].S.F-1]){
                        k=nxt[k]-1;
                        continue;
                    }
                    vis2[q[k].S.F-1]=1;
                    if (yy[q[k].S.F-1].F>=g[cnt].F){
                        merg(u,v);
                    }
                    k=nxt[k]-1;
                }
                ans[id]=zz[gg(q[id].S.F)];
                cnt++;
        }
        for (int j=i;j<(min(i+sq,(ll)q.size()));j++){
            if (!q[j].F){
                yy[q[j].S.F-1].F=q[j].S.S;
                vis[q[j].S.F-1]=0;
            }

        }
    }
    for (int i=0;i<q.size();i++){
        if (q[i].F)
        printf("%d \n",ans[i]);
    }
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:78:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int j=1;j<q.size();j++){
                  ~^~~~~~~~~
bridges.cpp:86:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0;i<q.size();i+=sq){
                  ~^~~~~~~~~
bridges.cpp:101:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j=0;j<yy.size();j++){
                      ~^~~~~~~~~~
bridges.cpp:110:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             while(cnt<g.size() && g[cnt].F>yal[j].F){
                   ~~~^~~~~~~~~
bridges.cpp:168:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while(cnt<g.size()){
               ~~~^~~~~~~~~
bridges.cpp:231:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0;i<q.size();i++){
                  ~^~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 0 / 27