/*input
6 8
0 1
1 2
2 3
3 4
4 5
5 0
5 3
-1
*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define int long long
#define double long double
#define f first
#define s second
#define mp make_pair
#define pb push_back
#define RE(i,n) for (int i = 1; i <= n; i++)
#define RED(i,n) for (int i = n; i > 0; i--)
#define REPS(i,n) for(int i = 1; (i*i) <= n; i++)
#define REP(i,n) for (int i = 0; i < (int)n; i++)
#define FOR(i,a,b) for (int i = a; i < b; i++)
#define REPD(i,n) for (int i = n-1; i >= 0; i--)
#define FORD(i,a,b) for (int i = a; i >= b; i--)
#define all(v) v.begin(),v.end()
#define pii pair<int,int>
#define vi vector<int>
#define vvi vector<vi>
#define print(arr) for (auto it = arr.begin(); it != arr.end(); ++it) cout << *it << " "; cout << endl;
#define debug(x) cout << x << endl;
#define debug2(x,y) cout << x << " " << y << endl;
#define debug3(x,y,z) cout << x << " " << y << " " << z << endl;
typedef tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
const int INF = 1e18+1;
const int MOD = 1e9+7;
const double PI = 3.14159265358979323846264338;
int raise(int a,int n,int m = MOD){
if(n == 0)return 1;
if(n == 1)return a;
int x = 1;
x *= raise(a,n/2,m);
x %= m;
x *= x;
x %= m;
if(n%2)x*= a;
x %= m;
return x;
}
int floor1(int n,int k){
if(n%k == 0 || n >= 0)return n/k;
return (n/k)-1;
}
int ceil1(int n,int k){
return floor1(n+k-1,k);
}
const int N = 1e6+1;
int deg[N];
bool vis[N];
vector<int> adj[N];
int n,q;
int edges = 0;
int comp = 0;
vector<int> three;
bool flag = 0;
int wow = 0;
int mxdeg = 0;
int scmax = 0;
int u;
void updatesdeg(int y,int hehe){
if(y > mxdeg){
scmax = mxdeg;
mxdeg = y;
wow = hehe;
}
else if(y > scmax){
scmax = y;
}
}
void dfs(int x,int p){
if(vis[x]){
flag = 1;
return;
}
vis[x] = 1;
for(int v:adj[x]){
if(v == p or v == u)continue;
dfs(v,x);
}
}
void ndfs(int x,int p){
if(vis[x]){
return;
}
vis[x] = 1;
edges += deg[x];
comp++;
for(int v:adj[x]){
if(v == p)continue;
ndfs(v,x);
}
}
void precheck(){
for(int v:adj[u]){
deg[v]--;
}
}
void postcheck(){
for(int v:adj[u]){
deg[v]++;
}
}
bool check(){
flag = 0;
bool fuck = 0;
for(int i = 0;i < n;i++){
vis[i] = 0;
if(i == u)continue;
if(deg[i] > 2){
fuck = 1;
}
}
if(fuck){
//cout << u << endl;
return 0;
}
for(int i = 0;i < n;i++){
if(vis[i] or i == u)continue;
dfs(i,-1);
}
return !flag;
}
void solve(){
cin >> n >> q;
REP(i,n)deg[i] = 0;
while(q--){
int x;cin >> x;
if(x == -1){
int sz =0;
if(mxdeg < 3){
REP(i,n){
vis[i] = 0;
}
int cnt = 0;
int found = 0;
REP(i,n){
if(vis[i])continue;
edges = 0;
comp = 0;
ndfs(i,-1);
edges /= 2;
if(comp-1 != edges){
cnt++;
found = comp;
}
edges = 0;
comp = 0;
}
if(cnt == 1){
cout << found << endl;
}
else if(cnt == 0){
cout << n << endl;
}
else cout << 0;
continue;
}
else if(mxdeg > 3){
//cout << "here haha\n";
u = wow;
precheck();
cout << check() << endl;
postcheck();
continue;
}
else{
set<int> chex;
for(int i = 0;i < three.size();i++){
chex.insert(three[i]);
for(int v:adj[three[i]]){
chex.insert(v);
}
}
int sz = 0;
for(auto it:chex){
u = it;
precheck();
sz += check();
postcheck();
}
cout << sz << endl;
}
}
else{
int y;cin >> y;
adj[x].pb(y);
adj[y].pb(x);
deg[x]++;
deg[y]++;
updatesdeg(deg[x],x);
updatesdeg(deg[y],y);
if(deg[x] == 3){
if(three.size())continue;
three.pb(x);
}
if(deg[y] == 3){
if(three.size())continue;
three.pb(y);
}
}
}
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//freopen(".in","r",stdin);freopen(".out","w",stdout);
int t = 1;
//cin >> t;
while(t--){
solve();
}
return 0;
}
Compilation message
rings.cpp: In function 'void solve()':
rings.cpp:206:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0;i < three.size();i++){
~~^~~~~~~~~~~~~~
rings.cpp:167:10: warning: unused variable 'sz' [-Wunused-variable]
int sz =0;
^~
/tmp/ccUve08M.o: In function `main':
rings.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/cc5GSUxO.o:grader.cpp:(.text.startup+0x0): first defined here
/tmp/cc5GSUxO.o: In function `main':
grader.cpp:(.text.startup+0x80): undefined reference to `Init(int)'
grader.cpp:(.text.startup+0xb2): undefined reference to `Link(int, int)'
grader.cpp:(.text.startup+0xd5): undefined reference to `CountCritical()'
collect2: error: ld returned 1 exit status
