Submission #350953

#	Time	Username	Problem	Language	Result	Execution time	Memory
350953		juggernaut	Parachute rings (IOI12_rings)	C++14	20 / 100	4091 ms	26596 KiB

rings

#ifndef EVAL
#include"grader.cpp"
#endif
#include<bits/stdc++.h>
using namespace std;
vector<int>g[1000005];
bool on[1000005],vis[1000005];
int n,deg[1000005];
int counter[5];
bool flag;
int cycle_size,cycle_number,cur_sz,global_answer;
void update_counter(int x,int y){
    counter[min(x,4)]+=y;
}
#define DEBUG(x) cout<<#x<<"="<<x<<"\n"
void go(int v,int p){
    if(on[v])return;
    cur_sz++;
    vis[v]=1;
    for(int to:g[v])if(to!=p){
        if(vis[to]){
            flag=true;
            continue;
        }
        go(to,v);
    }
}
bool check(){
    for(int i=0;i<n;i++)vis[i]=0;
    for(int i=0;i<n;i++){
        if(on[i])continue;
        if(deg[i]>2)return false;
        if(vis[i])continue;
        flag=false;
        go(i,i);
        if(flag)return false;
    }
    return true;
}
void Init(int N){
    n=N;
    counter[0]=n;
    global_answer=n;
}
int get_answer(){
    if(counter[4]){
        if(counter[4]!=1)return 0;
        for(int i=0;i<n;i++)
            if(deg[i]>3){
                on[i]=true;
                for(int to:g[i])deg[i]--,deg[to]--;
                int ans=check();
                for(int to:g[i])deg[i]++,deg[to]++;
                on[i]=false;
                return ans;
            }
    }else if(counter[3]){
        for(int i=0;i<n;i++)
            if(deg[i]>2){
                int ans=0;
                on[i]=true;
                for(int to:g[i])deg[i]--,deg[to]--;
                ans+=check();
                for(int to:g[i])deg[i]++,deg[to]++;
                on[i]=false;
                for(int to:g[i]){
                    on[to]=true;
                    for(int to2:g[to])deg[to]--,deg[to2]--;
                    ans+=check();
                    for(int to2:g[to])deg[to]++,deg[to2]++;
                    on[to]=false;
                }
                return ans;
            }
    }else{
        for(int i=0;i<n;i++)vis[i]=0;
        cycle_number=cycle_size=0;
        for(int i=0;i<n;i++){
            if(vis[i])continue;
            flag=false;
            cur_sz=0;
            go(i,i);
            if(flag)cycle_number++,cycle_size=cur_sz;
        }
        if(cycle_number==0)return n;
        else if(cycle_number==1)return cycle_size;
        else return 0;
    }
}
int mx=-1,cnt;
void Link(int x,int y){
    g[x].push_back(y);
    g[y].push_back(x);
    update_counter(deg[x],-1);
    update_counter(deg[y],-1);
    deg[x]++;
    deg[y]++;
    update_counter(deg[x],+1);
    update_counter(deg[y],+1);
    bool need_update=false;
    if(deg[x]>mx){
        mx=deg[x];
        cnt=1;
        need_update=true;
    }else if(deg[x]==mx)cnt++,need_update=true;
    if(deg[y]>mx){
        mx=deg[y];
        cnt=1;
        need_update=true;
    }else if(deg[y]==mx)cnt++,need_update=true;
    if(need_update)global_answer=get_answer();
}
int CountCritical(){
    return global_answer;
}
/*
7 13
-1
1 2
-1
0 5
-1
2 0
-1
3 2
-1
3 5
-1
4 3
-1

*/

Compilation message (stderr)

rings.cpp: In function 'int get_answer()':
rings.cpp:89:1: warning: control reaches end of non-void function [-Wreturn-type]
   89 | }
      | ^

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