Submission #1121201

#	Time	Username	Problem	Language	Result	Execution time	Memory
1121201		thelegendary08	Event Hopping (BOI22_events)	C++17	100 / 100	158 ms	27208 KiB

events

#include<bits/stdc++.h>
#define pb push_back
#define int long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define vout(v) cout<<#v<<' '; for(auto u : v){cout<<u<<' ';} cout<<'\n'
#define dout(a) cout<<a<<' '<<#a<<'\n'
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<'\n'
#define yn(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
#define left second
#define right first
using namespace std;
const int leg = 1e9 + 7;
const int mod = 998244353;
const int mxn = 1e5 + 5;
int tree[mxn * 4];
int n,q;
vector<pair<pii,int>> v;
int mn(int a, int b){
	if(a == -1)return b;
	if(b == -1)return a;
	return v[a].first.left < v[b].first.left ? a : b;
}
void update(int k, int x){
	k += n;
	tree[k] = x;
	for(k /=2; k>=1; k/=2){
		tree[k] = mn(tree[k*2], tree[k*2+1]);
	}
}
int quer(int l, int r){
	l += n;
	r += n;
	int ret = -1;
	while(l <= r){
		if(l % 2 == 1){
			ret = mn(ret, tree[l++]);
		}
		if(r % 2 == 0){
			ret = mn(ret, tree[r--]);
		}
		l/=2;
		r/=2;
	}
	return ret;
}

signed main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	//ifstream cin(".in");
	//ofstream cout(".out");
	cin>>n>>q;
	
	f0r(i,n){
		in2(a,b);
		v.pb({{b,a},i});
	}
	sort(rall(v));
	f0r(i,n){
		update(i, i);
	}
	vi dex(n);
	f0r(i,n)dex[v[i].second] = i;
	f0r(i,n){
		//out2(v[i].first.first, v[i].first.second);
	}
	
	vi nxt(n);
	
	f0r(i,n){
		int l = i;
		int r = n-1;
		while(l < r){
			int mid = l + (r - l + 1)/2;
			if(v[i].right.left <= v[mid].right.right){
				l = mid;
			}
			else{
				r = mid - 1;
			}
		}
		
		if(l != i){
			//out2(i+1, l);
			nxt[i] = quer(i+1, l);
		}
		else{
			nxt[i] = -1;
		}
	}
	//vout(nxt);
	vvi jmp(n, vi(17));
	f0r(i,n){
		jmp[i][0] = nxt[i];
	}
	FOR(i, 1, 17){
		f0r(j, n){
			if(jmp[j][i-1] == -1)jmp[j][i] = -1;
			else jmp[j][i] = jmp[jmp[j][i-1]][i-1];
		}
	}

	//vout(jmp[0]);
	f0r(i,n){
		//cout<<jmp[i][0]<<' ';
	}
	//out("");
	f0r(i, q){
		in2(a, b);
		if(a == b)out(0);
		else{
			a--;
			b--;
			swap(a,b);
			a = dex[a];
			b = dex[b];
			int goal = v[b].right.right;
			if(v[a].first.left <= goal && goal <= v[a].first.right){
				out(1);
			}
			else{
				//out3(a,b,goal);
				int cnt = 0;
				for(int i = 16; i>=0; i--){
					if(jmp[a][i] != -1){
						if(v[jmp[a][i]].right.left > goal){
							//out("HI");
							cnt += (1 << i);
							a = jmp[a][i];
						}
					}
				}
				
				if(nxt[a] == -1 || !(v[nxt[a]].right.left <= goal && goal <= v[nxt[a]].right.right))out("impossible");
				else out(cnt+2);
			}
			
		}
		
	}
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 30 / 30