oj.uz

Submission #1056009

# Submission time Handle Problem Language Result Execution time Memory
1056009 2024-08-13T07:07:38 Z allin27x Joker (BOI20_joker) C++17
25 / 100
 359 ms 25840 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long 
#define ll __int128
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

struct DSU{
	vector<int> par;
	vector<int> size;
	stack<int> rb;
	stack<char> tp;
	stack<int> bad;
	stack<pair<int,int>> edg;
	int nb;  int A = 0; int k;
	DSU(int n){
		k = n/2; par.resize(n); for(int i=0; i<n; ++i) par[i]=i;
		size.resize(n,1); nb = 0;
	}
	int get(int p){
		return par[p]==p? p: get(par[p]);
	}
	void unite(int a, int b){
		edg.push({a,b});
		if (get(a%k) == get(b%k)) {
			nb++; bad.push(1);
		} else bad.push(0);
		a = get(a); b = get(b);
		if (a==b){
			rb.push(-1);
			return;
		}
		if (size[a] > size[b]) swap(a,b);
		rb.push(a);
		size[b]+=size[a];
		par[a] = b;
	}
	void rollbackHelper(){
		int f = rb.top();
		rb.pop();
		nb -= bad.top(); bad.pop();
		edg.pop();
		if (f==-1) return;
		size[par[f]] -= size[f];
		par[f] = f;
	}
	void change(){
		stack<pair<int,int>> edA,edB;
		edB.push({edg.top().first, edg.top().second}); rollbackHelper();
		int a=0, b=1; tp.pop();
		while (A!=a && a!=b){
			if (tp.top()=='A'){
				a++; edA.push({edg.top().first, edg.top().second}); 
			} else {
				b++; edB.push({edg.top().first, edg.top().second}); 
			}
			tp.pop(); rollbackHelper();
		}
		while (!edB.empty()){
			unite(edB.top().first, edB.top().second);
			edB.pop();
			tp.push('B');
		}
		while (!edA.empty()){
			unite(edA.top().first, edA.top().second);
			edA.pop();
			tp.push('A'); 
		}
	}

	void rollback(){
		if (tp.top() == 'B') change();
		int f = rb.top();
		rb.pop();
		nb -= bad.top(); bad.pop();
		A--; tp.pop(); edg.pop();
		if (f==-1) return;
		size[par[f]] -= size[f];
		par[f] = f;
	}
};


const int N = 2e5+4;
int ans[N];
int edg[N][2];

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--; 
		edg[i][0] = a; edg[i][1] = b;
	}
	DSU dsu(2*n);
	for (int i=0; i<=m-1; i++){
		dsu.tp.push('A'); dsu.tp.push('A'); dsu.A+=2;
		dsu.unite(edg[i][0], edg[i][1]+n);
		dsu.unite(edg[i][0]+n, edg[i][1]);
	}
	int l=m; 
	for (int r = m-1; r>=0; r--){
		while (l>0 && dsu.nb){
			l--;
			dsu.rollback(); dsu.rollback();
		}
		ans[r]  = l;
		if (l==r+1) {dsu.rollback(); dsu.rollback(); l--;}
		dsu.unite(edg[r][0], edg[r][1] + n);
		dsu.unite(edg[r][0] + n, edg[r][1]);
		dsu.tp.push('B'); dsu.tp.push('B');
	}
	while (q--){
		int l, r; cin>>l>>r; l--; r--;
		cout<<(ans[r]<=l? "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;
}

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 0 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 0 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 186 ms 22356 KB Output is correct
4 Correct 359 ms 25784 KB Output is correct
5 Correct 94 ms 24788 KB Output is correct
6 Correct 93 ms 22228 KB Output is correct
7 Correct 101 ms 22468 KB Output is correct
8 Correct 119 ms 21200 KB Output is correct
9 Correct 127 ms 22484 KB Output is correct
10 Correct 181 ms 25840 KB Output is correct
11 Correct 124 ms 22228 KB Output is correct
12 Correct 127 ms 24788 KB Output is correct
13 Correct 100 ms 19952 KB Output is correct
14 Correct 115 ms 21208 KB Output is correct
15 Correct 157 ms 23480 KB Output is correct
16 Correct 173 ms 25556 KB Output is correct

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 0 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #5
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 0 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #6
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 0 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -