#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define bit(n,i) ((n>>i)&1)
#define all(x) x.begin(),x.end()
//#pragma GCC optimize("O2,unroll-loops")
//#pragma GCC target("avx,avx2,bmi,bmi2,sse,sse2,sse3,ssse3,sse4,popcnt")
//#define int long long
typedef long long ll;
typedef pair<int,int> pii;
typedef double ld;
typedef pair<ld,ld> pdd;
typedef pair<ll,ll> pll;
const ll maxn=2e5+69;
const ll offset=1e9;
const ll block_sz=317;
const ll inf=1e18;
const ll mod=1e9+7;
int n,m,q,par[maxn],col[maxn];
pii E[maxn];
int qr[maxn];
vector<pair<int,pii>> save;
pii Find(int u,int c=0)
{
if (par[u]<0) return {u,c^col[u]};
else
{
return Find(par[u],c^col[u]);
}
}
bool Union(int u,int v)
{
auto x=Find(u);
u=x.fi;
int cu=x.se;
auto y=Find(v);
v=y.fi;
int cv=y.se;
if (u==v)
{
if (cu==cv) return 0;
}
else
{
if (par[u]>par[v])
{
swap(u,v);
}
save.pb({v,{par[v],col[v]}});
if (cu==cv)
{
col[v]=1;
}
par[u]+=par[v];
par[v]=u;
}
return 1;
}
void undo(int x)
{
while(save.size()>x)
{
int v=save.back().fi;
int p=save.back().se.fi;
int c=save.back().se.se;
save.pop_back();
int u=par[v];
par[v]=p;
col[v]=c;
par[u]-=par[v];
}
}
int dp[maxn];
void Compute(int l,int r,int optl, int optr)
{
if (l>r) return;
int snap2=save.size();
int mid=l+r>>1;
// cerr<< "CHECKING "<<mid<<'\n';
// cerr<< l<<' '<<r<<' '<<snap2<<" snap2\n";
bool ok=1;
for1(i,l,mid)
{
if (!Union(E[i].fi,E[i].se))
{
ok=0;
}
// cerr<< i<<'\n';
}
int snap1=save.size();
// if (!ok) cout << "SKIP "<<mid<<'\n';
// cerr<< l<<' '<<r<<' '<<snap1<<" snap1\n";
// if (mid==3) cerr<< optl<<' '<<optr<<'\n';
if (ok)
{
int opt=optr;
while (opt>=max(optl,mid+1) &&Union(E[opt].fi,E[opt].se))
{
// cerr<< opt<<'\n';
opt--;
}
dp[mid]=opt;
// cerr<< l<<' '<<r<<' '<<snap1<<" roll1\n";
undo(snap1);
Compute(mid+1,r,dp[mid],optr);
}
// cerr<< l<<' '<<r<<' '<<snap2<<" roll2\n";
undo(snap2);
for2(i,optr,dp[mid]+1) Union(E[i].fi,E[i].se);
Compute(l,mid-1,optl,dp[mid]);
// cerr<< l<<' '<<r<<' '<<snap2<<" roll2\n";
undo(snap2);
// cerr<< "END "<<mid<<'\n';
}
void sol()
{
cin >> n>> m>> q;
for1(i,1,n) par[i]=-1;
for1(i,1,m)
{
cin >> E[i].fi>> E[i].se;
dp[i]=m+1;
}
Compute(1,m,1,m);
// for1(i,1,m) cout << dp[i]<<' ';
while (q--)
{
int l,r;cin>>l>>r;
if (dp[l-1]>r )
{
cout << "YES\n";
}
else
{
cout << "NO\n";
}
}
//par[1]=par[2]=par[3]=-1;
//cerr<< Union(1,2)<<' '<<Union(2,3)<<' '<<Union(1,3);
}
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
// freopen("GROUPDIV.inp","r",stdin);
// freopen("GROUPDIV.out","w",stdout);
int t=1;//cin >> t;
while (t--)
{
sol();
}
}
Compilation message
Joker.cpp: In function 'void undo(int)':
Joker.cpp:69:22: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
69 | while(save.size()>x)
| ~~~~~~~~~~~^~
Joker.cpp: In function 'void Compute(int, int, int, int)':
Joker.cpp:86:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
86 | int mid=l+r>>1;
| ~^~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Execution timed out |
2090 ms |
4444 KB |
Time limit exceeded |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Execution timed out |
2090 ms |
4444 KB |
Time limit exceeded |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Incorrect |
89 ms |
6592 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Execution timed out |
2090 ms |
4444 KB |
Time limit exceeded |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Execution timed out |
2090 ms |
4444 KB |
Time limit exceeded |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Execution timed out |
2090 ms |
4444 KB |
Time limit exceeded |
5 |
Halted |
0 ms |
0 KB |
- |