Submission #648833

#	Time	Username	Problem	Language	Result	Execution time	Memory
648833		ToroTN	Bridges (APIO19_bridges)	C++14	0 / 100	3053 ms	6644 KiB

bridges

#include<bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#define pb push_back
int n,m,num=sqrt(1),t,u[100005],v[100005],w[100005],e[100005];
int op[100005],a[100005],b[100005],mx=-1,group[100005],it1,it2;
int p[50005],sz[50005],e2[100005],top,ans[100005],hsh[100005];
int p2[50005],sz2[50005],l,r;
vector<pair<int,int> > g;
vector<tuple<int,int,int> > answer;
stack<pair<int,int> > stk;
int f(int a)
{
    if(p[a]==a)return a;
    return p[a]=f(p[a]);
}
void un(int b,int c)
{
    sz[f(c)]+=sz[f(b)];
    p[f(b)]=f(c);
}
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&u[i],&v[i],&w[i]);
        e[i]=w[i];
    }
    scanf("%d",&t);
    for(int i=1;i<=t;i++)
    {
        scanf("%d%d%d",&op[i],&a[i],&b[i]);
        group[i]=(i-1)/num+1;
        mx=max(mx,group[i]);
    }
    for(int i=1;i<=mx;i++)
    {
        l=(i-1)*num+1;
        r=min(t,i*num);
        //printf("l=%d r=%d\n",l,r);
        g.clear();
        answer.clear();
        for(int j=1;j<=m;j++)
        {
            g.pb({e[j],j});
        }
        sort(g.begin(),g.end());
        for(int j=0;j<=(int)(g.size()-1)/2;j++)
        {
            swap(g[j],g[(int)g.size()-j-1]);
        }
        for(int j=1;j<=m;j++)hsh[j]=0;
        for(int j=l;j<=r;j++)
        {
            if(op[j]==2)
            {
                answer.pb({b[j],a[j],j});
            }else ++hsh[a[j]];
        }
        sort(answer.begin(),answer.end());
        for(int j=0;j<=(int)(answer.size()-1)/2;j++)
        {
            swap(answer[j],answer[(int)answer.size()-j-1]);
        }
        /*for(int j=0;j<(int)g.size();j++)
        {
            printf("%d %d\n",g[j].X,g[j].Y);
        }
        printf("\n");
        for(int j=0;j<(int)answer.size();j++)
        {
            printf("%d %d %d\n",get<0>(answer[j]),get<1>(answer[j]),get<2>(answer[j]));
        }
        printf("\n");*/
        it1=0,it2=0;
        for(int j=1;j<=n;j++)p[j]=j,sz[j]=1;
        for(int j=1;j<=m;j++)e2[j]=e[j];
        top=1e9;
        while(it2<(int)answer.size())
        {
            auto [w2,node,idx]=answer[it2];
            if(it1<(int)g.size())
            {
                int w=g[it1].X,edge=g[it1].Y;
                if(w>=w2)
                {
                    if(f(u[edge])!=f(v[edge])&&hsh[edge]==0)
                    {
                        /*printf("it1=%d\n",it1);
                        printf("w=%d\n",w);
                        printf("edge=%d\n",edge);*/
                        un(u[edge],v[edge]);
                    }
                    top=w;
                    ++it1;
                    continue;
                }
            }
            for(int j=1;j<=n;j++)p2[j]=p[j],sz2[j]=sz[j];
            for(int j=l;j<=r;j++)
            {
                if(op[j]==1&&j<idx)
                {
                    e2[a[j]]=b[j];
                }
            }
            /*printf("%d %d\n",it1,it2);
            for(int j=1;j<=n;j++)
            {
                printf("%d ",f(j));
            }
            printf("\n");
            for(int j=1;j<=n;j++)
            {
                printf("%d ",sz[f(j)]);
            }
            printf("\n");*/
            for(int j=l;j<=r;j++)
            {
                if(op[j]==1)
                {
                    //printf("%d %d\n",j,a[j]);
                    if(e2[a[j]]>=b[idx])
                    {
                        if(f(u[a[j]])!=f(v[a[j]]))
                        {
                            un(u[a[j]],v[a[j]]);
                        }
                    }
                }
            }
            ans[idx]=sz[f(node)];
            for(int j=l;j<=r;j++)
            {
                if(op[j]==1&&j<idx)e2[a[j]]=e[a[j]];
            }
            for(int i=1;i<=n;i++)p[i]=p2[i],sz[i]=sz2[i];
            ++it2;
        }
        for(int j=l;j<=r;j++)
        {
            if(op[j]==1)
            {
                e[a[j]]=b[j];
            }
        }
    }
    for(int i=1;i<=t;i++)
    {
        if(op[i]==2)printf("%d\n",ans[i]);
    }
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:83:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   83 |             auto [w2,node,idx]=answer[it2];
      |                  ^
bridges.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
bridges.cpp:28:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         scanf("%d%d%d",&u[i],&v[i],&w[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:31:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |     scanf("%d",&t);
      |     ~~~~~^~~~~~~~~
bridges.cpp:34:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |         scanf("%d%d%d",&op[i],&a[i],&b[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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