#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
double cur = rngesus(0, MASK(60) - 1);
cur /= MASK(60) - 1;
return l + cur * (r - l);
}
template <class T1, class T2>
bool maximize(T1 &a, T2 b){
if (a < b) {a = b; return true;}
return false;
}
template <class T1, class T2>
bool minimize(T1 &a, T2 b){
if (a > b) {a = b; return true;}
return false;
}
template <class T>
void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
for(auto item: container) out << item << separator;
out << finish;
}
template <class T>
void remove_dup(vector<T> &a){
sort(ALL(a));
a.resize(unique(ALL(a)) - a.begin());
}
const int N = 2e5 + 69, BLOCK = 500;
struct DSU{
int n;
vector<pair<int,int>> parent;
vector<int> sz;
vector<pair<int,int>> history;
int is_valid;
DSU(int _n){
n = _n;
parent.resize(n+1); sz.resize(n+1);
reset();
}
void reset(){
for(int i = 1; i <= n; ++i) {
parent[i] = {i, 0};
sz[i] = 1;
}
is_valid = 1;
history.clear();
}
pair<int, int> find_set(int u){
if (u == parent[u].first) return parent[u];
pair<int, int> v = find_set(parent[u].first);
v.second ^= parent[u].second;
return v;
}
bool join_set(int x, int y, int w){
pair<int, int> u = find_set(x), v = find_set(y);
if (u.first != v.first){
if (sz[u.first] < sz[v.first]) swap(u, v);
parent[v.first] = make_pair(u.first, u.second ^ v.second ^ w);
sz[u.first] += sz[v.first];
history.push_back(make_pair(u.first, v.first));
return true;
}
if (u.second ^ v.second ^ w) {
if (is_valid == 1) history.push_back(make_pair(0, -1));
is_valid = 0;
}
return false;
}
int get_version(){return history.size();}
void roll_back(int target_version){
while(get_version() > target_version){
pair<int, int> V = history.back(); history.pop_back();
if (V.second == -1){
is_valid = 1;
}
else{
int u, v; tie(u, v) = V;
sz[u] -= sz[v];
parent[v] = {v, 0};
}
}
}
};
int n, m, q;
pair<int, int> edge[N];
pair<int, int> queries[N];
vector<int> queries_list[N];
int first_jorkit[N];
void dnc(int l, int r, int optL, int optR, DSU &mst){
if (l > r) return;
int state1 = mst.get_version();
int mid = (l + r) >> 1;
for(int i = 1; i < mid; ++i) mst.join_set(edge[i].first, edge[i].second, 1);
int opt = optR, state2 = mst.get_version();
while(mst.is_valid){
mst.join_set(edge[opt].first, edge[opt].second, 1);
opt--;
}
first_jorkit[mid] = opt;
mst.roll_back(state2);
dnc(mid+1, r, opt, optR, mst);
mst.roll_back(state1);
for(int j = optR; j > opt; --j) mst.join_set(edge[j].first, edge[j].second, 1);
dnc(l, mid-1,optL, opt, mst);
}
void solve(){
cin >> n >> m >> q;
for(int i = 1; i <= m; ++i){
cin >> edge[i].first >> edge[i].second;
}
for(int i = 0; i < q; ++i){
int l, r; cin >> l >> r;
queries[i] = {l, r};
}
DSU mst(n);
for(int i = 0; i < m; ++i) mst.join_set(edge[i].first, edge[i].second, 1);
if (mst.is_valid == 1){
for(int i= 0; i < q; ++i){
cout << "NO\n";
}
return;
}
mst.reset();
dnc(1, m, 1, m, mst);
// for(int i = 1; i <= m; ++i) cout << first_jorkit[i] << " ";
// cout << "\n";
for(int i = 0; i < q; ++i){
if (queries[i].second <= first_jorkit[queries[i].first]) cout << "YES\n";
else cout << "NO\n";
}
}
int main(void){
ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
clock_t start = clock();
solve();
cerr << "Time elapsed: " << clock() - start << " ms!\n";
return 0;
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |