Submission #357283

#	Time	Username	Problem	Language	Result	Execution time	Memory
357283		daniel920712	Parachute rings (IOI12_rings)	C++14	20 / 100	4046 ms	42768 KiB

rings

#include <stdio.h>
#include <stdlib.h>
#include <vector>
using namespace std;
int N;
int who;
vector < int > Next[1000005];
int deg[1000005];
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);
    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++)
    {
        ok=1;
        who=i;
        for(auto j:Next[i])
        {
            deg[j]--;
            if(deg[j]>=3) ok=0;
        }
        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;
        //if(ok) printf("aa %d\n",i);
    }
    return ans;

}

Compilation message (stderr)

rings.cpp: In function 'void F(int)':
rings.cpp:25:9: warning: unused variable 't' [-Wunused-variable]
   25 |     int t=0;
      |         ^

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