// Judges with GCC >= 12 only needs Ofast
// #pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
// MLE optimization
// #pragma GCC optimize("conserve-stack")
// Old judges
// #pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
// New judges. Test with assert(__builtin_cpu_supports("avx2"));
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
// Atcoder
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
- insert(x),erase(x)
- find_by_order(k): return iterator to the k-th smallest element
- order_of_key(x): the number of elements that are strictly smaller
*/
#include<bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
uniform_real_distribution<> pp(0.0,1.0);
#define ld long double
#define pii pair<int,int>
#define piii pair<pii,int>
#define mpp make_pair
#define fi first
#define se second
const int mod=1e9+7;
const int maxn=200005;
const int bl=650;
const int maxs=655;
const int maxm=200005;
const int maxq=1000005;
const int maxl=20;
const int maxa=1000000;
const int root=3;
const int base=101;
int n,m,s[maxn],t[maxn],res;
struct event{
int pu,pv;
bool cur;
};
namespace DSU{
bool check=true;
int par[maxn],d[maxn],sz[maxn];
vector<event> E;
void reset(){
check=true;E.clear();
for(int i=1;i<=n;i++) par[i]=i,d[i]=0,sz[i]=1;
}
pii findpar(int u){
if(u!=par[u]){
pii x=findpar(par[u]);
return {x.fi,x.se^d[u]};
}
return {u,0};
}
void unions(int u,int v,int t){
auto [pu,du]=findpar(u);
auto [pv,dv]=findpar(v);
if(pu==pv){
E.push_back({pu,pv,check});
if((du^t)!=dv) check=false;
return;
}
if(sz[pu]<sz[pv]) swap(pu,pv),swap(du,dv);
E.push_back({pu,pv,check});
par[pv]=pu;sz[pu]+=sz[pv];
d[pv]^=du^dv^t;
}
void roll_back(){
event e=E.back();
E.pop_back();
check=e.cur;
int pu=e.pu,pv=e.pv;
if(pu==pv) return;
d[pv]=0;par[pv]=pv;
sz[pu]-=sz[pv];
}
}
void dnc(int l,int r){
if(l==r){
DSU::unions(s[l],t[l],0);
res+=DSU::check;
DSU::roll_back();
return;
}
int mid=(l+r)>>1;
for(int i=r;i>mid;i--) DSU::unions(s[i],t[i],1);
dnc(l,mid);
for(int i=r;i>mid;i--) DSU::roll_back();
for(int i=l;i<=mid;i++) DSU::unions(s[i],t[i],1);
dnc(mid+1,r);
for(int i=l;i<=mid;i++) DSU::roll_back();
}
void solve(){
cin >> n >> m;
DSU::reset();
for(int i=1;i<=m;i++) cin >> s[i] >> t[i];
dnc(1,m);
cout << res << '\n';
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);cout.tie(NULL);
int test=1;//cin >> test;
while(test--) solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2396 KB |
Output is correct |
2 |
Correct |
2 ms |
2396 KB |
Output is correct |
3 |
Correct |
2 ms |
2520 KB |
Output is correct |
4 |
Correct |
1 ms |
2396 KB |
Output is correct |
5 |
Correct |
3 ms |
2396 KB |
Output is correct |
6 |
Correct |
2 ms |
2392 KB |
Output is correct |
7 |
Correct |
2 ms |
2396 KB |
Output is correct |
8 |
Correct |
2 ms |
2396 KB |
Output is correct |
9 |
Correct |
3 ms |
2780 KB |
Output is correct |
10 |
Correct |
2 ms |
2396 KB |
Output is correct |
11 |
Correct |
2 ms |
2396 KB |
Output is correct |
12 |
Correct |
2 ms |
2524 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
48 ms |
6096 KB |
Output is correct |
2 |
Correct |
99 ms |
6096 KB |
Output is correct |
3 |
Correct |
52 ms |
6212 KB |
Output is correct |
4 |
Correct |
94 ms |
6088 KB |
Output is correct |
5 |
Correct |
8 ms |
2908 KB |
Output is correct |
6 |
Correct |
92 ms |
6232 KB |
Output is correct |
7 |
Correct |
95 ms |
6296 KB |
Output is correct |
8 |
Correct |
105 ms |
6096 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
38 ms |
5924 KB |
Output is correct |
2 |
Correct |
41 ms |
6244 KB |
Output is correct |
3 |
Correct |
43 ms |
6100 KB |
Output is correct |
4 |
Correct |
1 ms |
2684 KB |
Output is correct |
5 |
Correct |
80 ms |
5864 KB |
Output is correct |
6 |
Correct |
77 ms |
6228 KB |
Output is correct |
7 |
Correct |
100 ms |
6252 KB |
Output is correct |
8 |
Correct |
103 ms |
6100 KB |
Output is correct |
9 |
Correct |
102 ms |
6280 KB |
Output is correct |
10 |
Correct |
108 ms |
6200 KB |
Output is correct |
11 |
Correct |
79 ms |
6088 KB |
Output is correct |
12 |
Correct |
93 ms |
6084 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
70 ms |
8792 KB |
Output is correct |
2 |
Correct |
76 ms |
9668 KB |
Output is correct |
3 |
Correct |
1 ms |
2512 KB |
Output is correct |
4 |
Correct |
123 ms |
6276 KB |
Output is correct |
5 |
Correct |
122 ms |
6332 KB |
Output is correct |
6 |
Correct |
109 ms |
6376 KB |
Output is correct |
7 |
Correct |
182 ms |
10448 KB |
Output is correct |
8 |
Correct |
176 ms |
9588 KB |
Output is correct |
9 |
Correct |
159 ms |
10252 KB |
Output is correct |
10 |
Correct |
143 ms |
10184 KB |
Output is correct |
11 |
Correct |
127 ms |
9680 KB |
Output is correct |
12 |
Correct |
154 ms |
10460 KB |
Output is correct |
13 |
Correct |
146 ms |
11056 KB |
Output is correct |
14 |
Correct |
204 ms |
9536 KB |
Output is correct |
15 |
Correct |
172 ms |
10440 KB |
Output is correct |
16 |
Correct |
168 ms |
10440 KB |
Output is correct |
17 |
Correct |
157 ms |
9596 KB |
Output is correct |
18 |
Correct |
132 ms |
9536 KB |
Output is correct |