oj.uz

Submission #1056057

# Submission time Handle Problem Language Result Execution time Memory
1056057 2024-08-13T07:29:46 Z allin27x Joker (BOI20_joker) C++17
25 / 100
 418 ms 29468 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; 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--;
		l = min(l,r+1);
		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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 1 ms 2396 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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 1 ms 2396 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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 213 ms 26480 KB Output is correct
4 Correct 418 ms 29224 KB Output is correct
5 Correct 106 ms 29136 KB Output is correct
6 Correct 96 ms 26320 KB Output is correct
7 Correct 123 ms 26324 KB Output is correct
8 Correct 123 ms 24556 KB Output is correct
9 Correct 154 ms 25800 KB Output is correct
10 Correct 183 ms 29144 KB Output is correct
11 Correct 132 ms 26324 KB Output is correct
12 Correct 142 ms 28884 KB Output is correct
13 Correct 100 ms 23764 KB Output is correct
14 Correct 122 ms 25040 KB Output is correct
15 Correct 163 ms 27584 KB Output is correct
16 Correct 178 ms 29468 KB Output is correct

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 1 ms 2396 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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 1 ms 2396 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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Incorrect 1 ms 2396 KB Output isn't correct
6 Halted 0 ms 0 KB -