Submission #357574

#	Time	Username	Problem	Language	Result	Execution time	Memory
357574		daniel920712	Parachute rings (IOI12_rings)	C++14	0 / 100	1231 ms	60304 KiB

rings

#include <stdio.h>
#include <stdlib.h>
#include <vector>
using namespace std;
int N;
int who,x,y;
vector < int > Next[1000005];
int deg[1000005];
int big[1000005];
int con[1000005];
int tt=0;
bool have[1000005];
int ok=1;
void Init(int N_)
{
    N = N_;
}

void Link(int A, int B)
{
    Next[A].push_back(B);
    Next[B].push_back(A);
    if(deg[A]==2)
    {
        tt++;
        for(auto i:Next[A]) con[i]++;
    }
    if(deg[A]==3)
    {
        for(auto i:Next[A]) if(i!=B) con[i]--;
    }

    if(deg[B]==2)
    {
        tt++;
        for(auto i:Next[B]) con[i]++;
    }
    if(deg[B]==3)
    {
        for(auto i:Next[B]) if(i!=A) con[i]--;
    }
    deg[A]++;
    deg[B]++;

}
void F(int here)
{
    int t=0;
    have[here]=1;
    for(auto i:Next[here]) if(!have[i]&&i!=who) F(i);
}
int CountCritical()
{
    int ans=0;
    int i,j;
    for(i=0;i<N;i++)
    {
        if(deg[i]>=3)
        {
            break;
        }
    }
    if(i==N)
    {
        x=y=0;
        ok=1;
        who=-1;
        for(j=0;j<N;j++) have[j]=0;
        for(j=0;j<N;j++)
        {
            if(deg[j]==0) have[j]=1;
            if(deg[j]==1&&!have[j]) F(j);
        }
        for(j=0;j<N;j++)
        {
            if(!have[j])
            {
                who=-1;
                x++;
                y=0;
                F(j);
            }
            ans+=x;
        }

        if(x==0) return N;
        if(x==1) return y;
        return 0;
    }
    for(i=0;i<N;i++)
    {
        ok=1;
        who=i;
        //printf("%d %d %d\n",i,con[i],tt);
        if(deg[i]>=3)
        {
            if(tt-con[i]>1) continue;
        }
        else if(tt-con[i]) continue;

        //printf("aa %d\n",i);
        for(auto j:Next[i]) deg[j]--;
        if(ok)
        {
            for(j=0;j<N;j++) have[j]=0;
            have[i]=1;
            for(j=0;j<N;j++)
            {
                if(deg[j]==0) have[j]=1;
                if(deg[j]==1&&!have[j]) F(j);
                if(deg[j]>=3&&i!=j) ok=0;
            }
            for(j=0;j<N;j++) if(!have[j]) ok=0;
        }

        for(auto j:Next[i]) deg[j]++;
        ans+=ok;
    }
    return ans;

}

Compilation message (stderr)

rings.cpp: In function 'void F(int)':
rings.cpp:48:9: warning: unused variable 't' [-Wunused-variable]
   48 |     int t=0;
      |         ^

• Subtask 1: 0 / 20
• Subtask 2: 0 / 17
• Subtask 3: 0 / 18
• Subtask 4: 0 / 14
• Subtask 5: 0 / 31