oj.uz

Submission #1056006

# Submission time Handle Problem Language Result Execution time Memory
1056006 2024-08-13T07:05:49 Z allin27x Joker (BOI20_joker) C++17
25 / 100
 225 ms 41052 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 && r!=0) {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 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 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 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 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 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 222 ms 24660 KB Output is correct
4 Correct 95 ms 41052 KB Output is correct
5 Correct 104 ms 27088 KB Output is correct
6 Correct 102 ms 24528 KB Output is correct
7 Correct 112 ms 24528 KB Output is correct
8 Correct 129 ms 22992 KB Output is correct
9 Correct 183 ms 24664 KB Output is correct
10 Correct 225 ms 27608 KB Output is correct
11 Correct 166 ms 24532 KB Output is correct
12 Correct 160 ms 27056 KB Output is correct
13 Correct 106 ms 22228 KB Output is correct
14 Correct 125 ms 23404 KB Output is correct
15 Correct 164 ms 25812 KB Output is correct
16 Correct 187 ms 27724 KB Output is correct

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 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 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 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 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 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 -