// Why so serious
#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 2e5+5;
const string NAME = "";
int cnt=0;
struct DSU{
pair<int,bool> p[MAXN];
int sz[MAXN];
bool bipartite[MAXN];
stack<pair<int,pair<int,bool>>> historyA,historyB;
void save(int a, int b){
historyA.ins(a,mp(sz[a],bipartite[a]));
historyB.ins(b,p[b]);
}
void rollback(){
if(historyA.empty()) return;
sz[historyA.top().fi]=historyA.top().se.fi;
cnt-=bipartite[historyA.top().fi]^1;
bipartite[historyA.top().fi]=historyA.top().se.se;
cnt+=bipartite[historyA.top().fi]^1;
p[historyB.top().fi]=historyB.top().se;
historyA.pop(), historyB.pop();
}
void init(int n){
for(int i = 1; i<=n; ++i)
p[i]=mp(i,0);
fill(sz+1,sz+n+1,1);
fill(bipartite+1,bipartite+n+1,1);
}
pair<int,int> Find(int u){
bool color=0;
while(u!=p[u].fi){
color^=p[u].se;
u=p[u].fi;
}
return mp(u,color);
}
void Union(int a, int b){
pair<int,int> parentA=Find(a), parentB=Find(b);
a=parentA.fi, b=parentB.fi;
if(sz[a]<sz[b]) swap(a,b);
save(a,b), cnt-=(bipartite[a]^1);
if(a==b&&parentA.se==parentB.se) bipartite[a]=0;
else if(a!=b){
p[b]=mp(a,parentA.se^parentB.se^1);
sz[a]+=sz[b], bipartite[a]&=bipartite[b];
}
cnt+=bipartite[a]^1;
}
}dsu;
int n,m,q,last[MAXN],L,R;
pair<int,int> edge[MAXN];
void dnc(int l, int r, int optl, int optr){
if(l>r) return;
int mid=(l+r)>>1, curL=L, curR=R;
while(L<mid-1) ++L, dsu.Union(edge[L].fi,edge[L].se);
while(R>optr+1) --R, dsu.Union(edge[R].fi,edge[R].se);
while(cnt==0&&R>max(L,optl-1)+1) --R, dsu.Union(edge[R].fi,edge[R].se);
last[mid]=R-1;
while(R<optr+1) ++R, dsu.rollback();
if(mid+1<=r) dnc(mid+1,r,last[mid],optr);
if(l<=mid-1){
while(R<curR) ++R, dsu.rollback();
while(L+1>(l+mid-1)>>1) --L, dsu.rollback();
dnc(l,mid-1,optl,last[mid]);
}
while(R<curR) ++R, dsu.rollback();
while(L>curL) --L, dsu.rollback();
}
int main()
{
tt;
if(fopen((NAME + ".INP").c_str(), "r")) fo;
cin >> n >> m >> q;
for(int i = 1; i<=m; ++i)
cin >> edge[i].fi >> edge[i].se;
dsu.init(n);
L=0, R=m+1;
dnc(1,m,1,m);
while(q--){
int l,r;
cin >> l >> r;
if(r<=last[l]) cout << "YES\n";
else cout << "NO\n";
}
}
컴파일 시 표준 에러 (stderr) 메시지
Joker.cpp: In function 'int main()':
Joker.cpp:4:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
4 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:91:45: note: in expansion of macro 'fo'
91 | if(fopen((NAME + ".INP").c_str(), "r")) fo;
| ^~
Joker.cpp:4:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
4 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:91:45: note: in expansion of macro 'fo'
91 | if(fopen((NAME + ".INP").c_str(), "r")) fo;
| ^~
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