Submission #1113869

#	Time	Username	Problem	Language	Result	Execution time	Memory
1113869		thelegendary08	Fire (BOI24_fire)	C++17	21 / 100	2081 ms	76548 KiB

Main

#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) 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';}
const int leg = 1e9 + 7;
const int mod = 998244353;
using namespace std;
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	//ifstream cin(".in");
	//ofstream cout(".out");
	in2(n,m);
	vpii v;
	f0r(i,n){
		in2(a,b);
		v.pb({a,b});
	}
	sort(all(v));
	vpii w;
	int mx = -1;
	f0r(i, n){
		if(v[i].second + (v[i].first > v[i].second) * m > mx){
			w.pb(v[i]);
			mx = v[i].second + (v[i].first > v[i].second) * m;
		}
	}
	n = w.size();
	
	f0r(i, n){
		//out2(w[i].first, w[i].second);
	}
	
	bool ok = 1;
	f0r(i, n-1){
		if(w[i].first < w[i].second){
			if(!(w[i+1].first <= w[i].second && w[i].first <= w[i+1].first))ok = 0;
		}
		else{
			if(!(w[i+1].first >= w[i].first || w[i+1].first <= w[i].second))ok = 0;
		}
	}
	if(w[n-1].first < w[n-1].second || w[n-1].second < w[0].first)ok = 0;
	if(!ok || n < 2)out(-1);
	else{
		int ptr = 0;
		vi nxt(n);
		f0r(i, n){
			int save = ptr;
			if(w[i].first < w[i].second){
				while(w[i].first <= w[ptr].first && w[ptr].first <= w[i].second){
					ptr++;
					ptr %= n;
					if(ptr == save){
						break;
					}
				}
			}
			else{
				while(w[ptr].first >= w[i].first || w[ptr].first <= w[i].second){
					ptr++;
					ptr %= n;
					if(ptr == save)break;
				}
			}
			if(ptr != 0)nxt[i] = ptr - 1;
		
			else nxt[i] = n-1;
		}
		//vout(nxt);
		
		
		pii jmp[n][20];
		f0r(i, n){
			int loops = 0;
			if(w[i].first > w[i].second)loops++;
			if(w[i].second > w[nxt[i]].second)loops++;
			jmp[i][0] = {nxt[i], loops};
		}
		FOR(i, 1, 20){
			f0r(j,n){
				jmp[j][i] = {jmp[jmp[j][i-1].first][i-1].first, (jmp[j][i-1].second + jmp[jmp[j][i-1].first][i-1].second - (w[jmp[j][i-1].first].first > w[jmp[j][i-1].first].second))};
			}
		}
		f0r(i, n){
			//out2(jmp[i][0].first, jmp[i][0].second);
		}
		//out("");
		f0r(i, n){
			//out2(jmp[i][1].first, jmp[i][1].second);
		}
		
		int ans = 4e18;
		f0r(i, n){
			if(jmp[i][0].second == 1 && w[jmp[i][0].first].second >= w[i].first){
				ans = min(ans, 2ll);
			}
			else{
				int cur = 0;
				int dex = i;
				int loops = 0;
				for(int j = 19; j>=0; j--){
					if(loops == 0){
						if(jmp[dex][j].second == 1 && w[jmp[dex][j].first].second < w[i].first){
							cur += (1 << j);
							loops++;
							dex = jmp[dex][j].first;
							//out("path 1");
						}
						else if(jmp[dex][j].second == 0){
							cur += (1 << j);
							dex = jmp[dex][j].first;
							//out("path 2");
						}
					}
					else if(loops == 1){
						if((jmp[dex][j].second == 0 || (jmp[dex][j].second == 1  && w[dex].first > w[dex].second)) && w[jmp[dex][j].first].second < w[i].first){
							cur += (1 << j);
							dex = jmp[dex][j].first;
							//out("path 3");
						}
					}
					//dout2(loops, dex);
				}
				//out(cur+2);
				ans = min(ans, cur + 2);
			}
			
		}
		if(ans != 4e18)out(ans);
		else out(-1);
	}
	
	
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 17
• Subtask 3: 0 / 9
• Subtask 4: 0 / 13
• Subtask 5: 21 / 21
• Subtask 6: 0 / 26