#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9+7;
#define forn(i,n) for(int i=0; i<n; i++)
#define readv(a,n) vector<int>a(n);forn(i,n)cin>>a[i];
#define readvv(a,n,m) vector<vector<int>> a(n,vector<int>(m));forn(i,n)forn(j,m)cin>>a[i][j];
#define all(a) a.begin(), a.end()
#define _max(x,y) x = max(x,y)
#define _min(x,y) x = min(x,y)
// #define f first
// #define s second
const int N = 2e5+4;
const int SQRT = 460;
int ans[N];
struct qr{
int l, r, i;
bool operator<(qr b){
return make_pair(l/SQRT, r) < make_pair(b.l/SQRT,b.r);
}
};
vector<qr> queries[SQRT];
int edges[N][2];
int e1[2*N];
void build1(int N) {for (int i=0; i<N; i++) e1[i] = -1;}
int get1(int x) { return e1[x] < 0 ? x : e1[x] = get1(e1[x]); }
bool conn1(int a, int b) { return get1(a) == get1(b); }
int size1(int x) { return -e1[get1(x)]; }
void unite1(int x, int y) {
x = get1(x), y = get1(y);
if (x == y) return;
if (e1[x] > e1[y]) swap(x, y);
e1[x] += e1[y];
e1[y] = x;
}
int nd = 0;
int ch[4*SQRT+6];
int e2[2*N];
void build2(int N) {for (int i=0; i<N; i++) e2[i] = -1;}
int get2(int x) {
if (e2[x] < 0) return x;
ch[nd++] = x;
return e2[x] = get2(e2[x]);
}
bool conn2(int a, int b) { return get2(a) == get2(b); }
int size2(int x) { return -e2[get2(x)]; }
void unite2(int x, int y) {
x = get2(x), y = get2(y);
if (x == y) return;
if (e2[x] > e2[y]) swap(x, y);
e2[x] += e2[y];
e2[y] = x;
}
int st[2*N];
void solve(){
int n,m,q; cin>>n>>m>>q;
for (int i=0; i<m; i++){
int a,b; cin>>a>>b; a--;b--; edges[i][0]=a; edges[i][1] = b;
}
for (int i=0; i<q; i++){
int l,r; cin>>l>>r; l--; r--;
qr p; p.l=l;p.r=r;p.i=i;
queries[l/SQRT].push_back(p);
}
for (int i=0; i<SQRT; i++) sort(queries[i].begin(), queries[i].end());
build1(2*n); build2(2*n);
int fM =0;
for (int t=0; t<SQRT; t++){
for (int i=0; i<2*n; i++) e2[i] = e1[i],st[i] = e2[i];
if (t*SQRT >= m) break;
int fm = 0;
int i = m-1; int j = queries[t].size()-1;
while (i>=0){
if (j<0) break;
qr p = queries[t][j];
while (p.r == i){
int f = 0;
nd = 0;
for (int ll=t*SQRT; ll<p.l; ll++){
if (conn2(edges[ll][0],edges[ll][1])) f++;
unite2(edges[ll][0]+n, edges[ll][1]);
unite2(edges[ll][0], edges[ll][1]+n);
}
for (int rr =0; rr<nd; rr++){
e2[ch[rr]] = st[ch[rr]];
}
if (f || fm || fM) ans[p.i] = 1;
j--;
if (j<0) break;
p = queries[t][j];
}
if (j<0) break;
nd = 0;
fm += conn2(edges[i][0], edges[i][1]);
unite2(edges[i][0] + n, edges[i][1]);
unite2(edges[i][0], edges[i][1] + n);
for (int rr =0; rr<nd; rr++){
st[ch[rr]] = e2[ch[rr]];
}
i--;
}
for (int ll=SQRT*t; ll<min(m, SQRT*t + SQRT); ll++){
fM += conn1(edges[ll][0], edges[ll][1]);
unite1(edges[ll][0] + n, edges[ll][1]);
unite1(edges[ll][0], edges[ll][1] + n);
}
}
for (int i=0;i<q; i++) cout<<(ans[i]?"YES\n":"NO\n");
}
signed main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
int t=1;
while(t--){
solve();
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Correct |
1 ms |
6492 KB |
Output is correct |
3 |
Correct |
1 ms |
6492 KB |
Output is correct |
4 |
Correct |
1 ms |
6492 KB |
Output is correct |
5 |
Incorrect |
1 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Correct |
1 ms |
6492 KB |
Output is correct |
3 |
Correct |
1 ms |
6492 KB |
Output is correct |
4 |
Correct |
1 ms |
6492 KB |
Output is correct |
5 |
Incorrect |
1 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Correct |
1 ms |
6492 KB |
Output is correct |
3 |
Correct |
78 ms |
12984 KB |
Output is correct |
4 |
Correct |
95 ms |
10940 KB |
Output is correct |
5 |
Correct |
96 ms |
11868 KB |
Output is correct |
6 |
Correct |
83 ms |
12156 KB |
Output is correct |
7 |
Correct |
79 ms |
11860 KB |
Output is correct |
8 |
Correct |
67 ms |
11704 KB |
Output is correct |
9 |
Correct |
79 ms |
12028 KB |
Output is correct |
10 |
Correct |
101 ms |
11960 KB |
Output is correct |
11 |
Correct |
80 ms |
11760 KB |
Output is correct |
12 |
Correct |
98 ms |
11740 KB |
Output is correct |
13 |
Correct |
58 ms |
11704 KB |
Output is correct |
14 |
Correct |
70 ms |
11816 KB |
Output is correct |
15 |
Correct |
91 ms |
11704 KB |
Output is correct |
16 |
Correct |
103 ms |
11888 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Correct |
1 ms |
6492 KB |
Output is correct |
3 |
Correct |
1 ms |
6492 KB |
Output is correct |
4 |
Correct |
1 ms |
6492 KB |
Output is correct |
5 |
Incorrect |
1 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Correct |
1 ms |
6492 KB |
Output is correct |
3 |
Correct |
1 ms |
6492 KB |
Output is correct |
4 |
Correct |
1 ms |
6492 KB |
Output is correct |
5 |
Incorrect |
1 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Correct |
1 ms |
6492 KB |
Output is correct |
3 |
Correct |
1 ms |
6492 KB |
Output is correct |
4 |
Correct |
1 ms |
6492 KB |
Output is correct |
5 |
Incorrect |
1 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |