oj.uz

Submission #908087

# Submission time Handle Problem Language Result Execution time Memory
908087 2024-01-16T07:48:46 Z JakobZorz Parachute rings (IOI12_rings) C++17
37 / 100
 3369 ms 206012 KB 
#include<iostream>
#include<vector>
#include<unordered_set>
using namespace std;
typedef long long ll;

int n;
vector<int>nodes[(int)1e6];
unordered_set<int>num3;
int num4=-1;
int num3n[(int)1e6];
int num_cycles;
unordered_set<int>cycle;
unordered_set<ll>adj;
ll toll(ll a,ll b){
    return a+(b<<32);
}

int dsu_parent[(int)1e6];
int dsu_get(int a){
    if(dsu_parent[a]<0)
        return a;
    return dsu_parent[a]=dsu_get(dsu_parent[a]);
}

void dsu_merge(int a,int b){
    a=dsu_get(a);
    b=dsu_get(b);
    if(a==b)
        return;
    if(dsu_parent[a]>dsu_parent[b])
        swap(a,b);
    dsu_parent[a]+=dsu_parent[b];
    dsu_parent[b]=a;
}

void Init(int N){
    n=N;
    for(int i=0;i<1e6;i++)
        dsu_parent[i]=-1;
}

int cvis;
int vis[(int)1e6];
int dfs(int node,int d,int end){ // -1 = dead end
    int pv=vis[node];
    vis[node]=cvis;
    
    for(int ne:nodes[node]){
        if(ne==end&&d>1)
            return end;
        if(vis[ne]!=cvis&&vis[ne]!=0)
            return ne;
            
        if(vis[ne]==0){
            int r=dfs(ne,d+1,end);
            if(r!=-1)
                return r;
        }
    }
    
    vis[node]=pv;
    return -1;
}

void conn(int a,int b){
    adj.insert(toll(a,b));
    nodes[a].push_back(b);
    if(nodes[a].size()==3){
        num3.insert(a);
        for(int ne:nodes[a])
            num3n[ne]++;
    }
    
    if(nodes[a].size()==4){
        num3.erase(a);
        if(num4==-1)
            num4=a;
        else
            num4=-2;
        for(int ne:nodes[a])
            num3n[ne]--;
    }
}

void Link(int a,int b){
    conn(a,b);
    conn(b,a);
    
    if(dsu_get(a)==dsu_get(b)){
        if(num_cycles==0){
            cvis++;
            dfs(a,0,a);
            for(int i=0;i<1e6;i++)
                if(vis[i]==cvis){
                    cycle.insert(i);
                }
            num_cycles=1;
        }else if(num_cycles==1){
            if(vis[a])
                swap(a,b);
            if(vis[a]){
                if(vis[a]!=vis[b]){
                    num_cycles=2;
                    return;
                }
                
                if(cycle.count(a)&&cycle.count(b)){
                    cycle={a,b};
                }else{
                    num_cycles=2;
                }
                return;
            }
            
            unordered_set<int>s;
            int cnt=0;
            for(int ne:nodes[a]){
                cvis++;
                vis[a]=cvis;
                int r=dfs(ne,1,a);
                if(r!=-1){
                    s.insert(r);
                    cnt++;
                }
            }
            
            //cout<<"CNT: "<<cnt<<"\n";
            if(s.size()==1&&cnt==2){
                int center=*s.begin();
                if(cycle.find(center)!=cycle.end()){
                    cycle={center};
                    //cout<<"CYCLE: "<<center<<"\n";
                }else
                    num_cycles=2;
            }else if(s.size()==2&&cnt==2){
                int a1=*s.begin();
                s.erase(s.begin());
                int a2=*s.begin();
                if(adj.count(toll(a1,a2))){
                    cycle={a1,a2};
                }else{
                    num_cycles=2;
                }
            }else{
                num_cycles=2;
            }
        }else{
            num_cycles=2;
        }
    }else{
        dsu_merge(a,b);
    }
}

bool check(int i){
    bool in_cycle=true;
    if(num_cycles==1)
        in_cycle=cycle.find(i)!=cycle.end();
    /*cout<<"checking "<<i<<"\n";
    cout<<(num3n[i]==(int)num3.size())<<" ";
    cout<<(nodes[i].size()==3&&num3n[i]==(int)num3.size()-1)<<" ";
    cout<<in_cycle<<"\n";*/
    return (num3n[i]==(int)num3.size()||(nodes[i].size()==3&&num3n[i]==(int)num3.size()-1))&&in_cycle;
}

int CountCritical(){
    if(num_cycles>=2)
        return 0;
    if(num3.size()>4)
        return 0;
    if(num4==-2)
        return 0;
    if(num4!=-1){
        bool in_cycle=true;
        if(num_cycles==1)
            in_cycle=cycle.find(num4)!=cycle.end();
        return num3n[num4]==num3.size()&&in_cycle;
    }
    
    if(num3.empty()&&num_cycles==1)
        return cycle.size();
    
    if(num3.empty())
        return n;
    
    int res=0;
    unordered_set<int>s;
    for(int i:num3){
        for(int ne:nodes[i]){
            if(check(ne))
                s.insert(ne);
        }
        if(check(i))
            s.insert(i);
    }
    return (int)s.size();
}

Compilation message

rings.cpp: In function 'int CountCritical()':
rings.cpp:178:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::unordered_set<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  178 |         return num3n[num4]==num3.size()&&in_cycle;
      |                ~~~~~~~~~~~^~~~~~~~~~~~~
rings.cpp:187:9: warning: unused variable 'res' [-Wunused-variable]
  187 |     int res=0;
      |         ^~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 31320 KB Output is correct
2 Correct 11 ms 31836 KB Output is correct
3 Correct 11 ms 31832 KB Output is correct
4 Correct 10 ms 31576 KB Output is correct
5 Correct 11 ms 31836 KB Output is correct
6 Correct 12 ms 32212 KB Output is correct
7 Correct 9 ms 31324 KB Output is correct
8 Correct 11 ms 31836 KB Output is correct
9 Correct 11 ms 31924 KB Output is correct
10 Correct 11 ms 31836 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1119 ms 91380 KB Output is correct
2 Correct 2300 ms 137820 KB Output is correct
3 Correct 3369 ms 151532 KB Output is correct
4 Correct 2860 ms 148940 KB Output is correct
5 Correct 3293 ms 152696 KB Output is correct
6 Correct 3279 ms 206012 KB Output is correct
7 Correct 3229 ms 148168 KB Output is correct
8 Correct 2644 ms 144012 KB Output is correct
9 Correct 2843 ms 150172 KB Output is correct
10 Correct 2192 ms 145440 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 31320 KB Output is correct
2 Correct 11 ms 31836 KB Output is correct
3 Correct 11 ms 31832 KB Output is correct
4 Correct 10 ms 31576 KB Output is correct
5 Correct 11 ms 31836 KB Output is correct
6 Correct 12 ms 32212 KB Output is correct
7 Correct 9 ms 31324 KB Output is correct
8 Correct 11 ms 31836 KB Output is correct
9 Correct 11 ms 31924 KB Output is correct
10 Correct 11 ms 31836 KB Output is correct
11 Correct 13 ms 31836 KB Output is correct
12 Correct 15 ms 32604 KB Output is correct
13 Correct 15 ms 32604 KB Output is correct
14 Incorrect 14 ms 32092 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 31320 KB Output is correct
2 Correct 11 ms 31836 KB Output is correct
3 Correct 11 ms 31832 KB Output is correct
4 Correct 10 ms 31576 KB Output is correct
5 Correct 11 ms 31836 KB Output is correct
6 Correct 12 ms 32212 KB Output is correct
7 Correct 9 ms 31324 KB Output is correct
8 Correct 11 ms 31836 KB Output is correct
9 Correct 11 ms 31924 KB Output is correct
10 Correct 11 ms 31836 KB Output is correct
11 Correct 13 ms 31836 KB Output is correct
12 Correct 15 ms 32604 KB Output is correct
13 Correct 15 ms 32604 KB Output is correct
14 Incorrect 14 ms 32092 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 31320 KB Output is correct
2 Correct 11 ms 31836 KB Output is correct
3 Correct 11 ms 31832 KB Output is correct
4 Correct 10 ms 31576 KB Output is correct
5 Correct 11 ms 31836 KB Output is correct
6 Correct 12 ms 32212 KB Output is correct
7 Correct 9 ms 31324 KB Output is correct
8 Correct 11 ms 31836 KB Output is correct
9 Correct 11 ms 31924 KB Output is correct
10 Correct 11 ms 31836 KB Output is correct
11 Correct 1119 ms 91380 KB Output is correct
12 Correct 2300 ms 137820 KB Output is correct
13 Correct 3369 ms 151532 KB Output is correct
14 Correct 2860 ms 148940 KB Output is correct
15 Correct 3293 ms 152696 KB Output is correct
16 Correct 3279 ms 206012 KB Output is correct
17 Correct 3229 ms 148168 KB Output is correct
18 Correct 2644 ms 144012 KB Output is correct
19 Correct 2843 ms 150172 KB Output is correct
20 Correct 2192 ms 145440 KB Output is correct
21 Correct 13 ms 31836 KB Output is correct
22 Correct 15 ms 32604 KB Output is correct
23 Correct 15 ms 32604 KB Output is correct
24 Incorrect 14 ms 32092 KB Output isn't correct
25 Halted 0 ms 0 KB -