Submission #113973

#	Time	Username	Problem	Language	Result	Execution time	Memory
113973		dorijanlendvaj	Boat (APIO16_boat)	C++14	27 / 100	1177 ms	72440 KiB

boat

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define x first
#define y second
#define pii pair<int,int>
#define pb push_back
#define eb emplace_back

using namespace std;
using namespace __gnu_pbds;

typedef long long int ll;
typedef unsigned long long int ull;
int MOD=1000000007;
int MOD2=998244353;
vector<int> bases;
const ll LLINF=1ll<<60;
const char en='\n';

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void yes() {cout<<"YES"<<en; exit(0);}
void no() {cout<<"NO"<<en; exit(0);}
inline int rund() {int x576363482791fuweh=rng();return abs(x576363482791fuweh)%RAND_MAX;}
template<class T>
void prVec(vector<T> w)
{
	cout<<w.size()<<endl;
	for (int i=0;i<int(w.size())-1;++i) cout<<w[i]<<' ';
	if (w.size()) cout<<w[w.size()-1]<<endl;
}

void M998()
{
	swap(MOD,MOD2);
}

ll raand()
{
	ll a=rund();
	a*=RAND_MAX;
	a+=rund();
    return a;
}

#define rand raand

ll raaand()
{
	return raand()*(MOD-7)+raand();
}

string to_upper(string a)
{
	for (int i=0;i<(int)a.size();++i) if (a[i]>='a' && a[i]<='z') a[i]-='a'-'A';
	return a;
}

string to_lower(string a)
{
	for (int i=0;i<(int)a.size();++i) if (a[i]>='A' && a[i]<='Z') a[i]+='a'-'A';
	return a;
}

ll sti(string a)
{
	ll k=0;
	for (int i=0;i<(int)a.size();++i)
	{
		k*=10;
		k+=a[i]-'0';
	}
	return k;
}

string its(ll k)
{
	if (k==0) return "0";
	string a;
	while (k)
	{
		a.push_back((k%10)+'0');
		k/=10;
	}
	reverse(a.begin(),a.end());
	return a;
}

ll min(ll a,int b)
{
	if (a<b) return a;
	return b;
}

ll min(int a,ll b)
{
	if (a<b) return a;
	return b;
}

ll max(ll a,int b)
{
	if (a>b) return a;
	return b;
}

ll max(int a,ll b)
{
	if (a>b) return a;
	return b;
}

ll gcd(ll a,ll b)
{
	if (b==0) return a;
	return gcd(b,a%b);
}

ll lcm(ll a,ll b)
{
	return a/gcd(a,b)*b;
}

template<class T,class K>
pair<T,K> mp(T a,K b)
{
	return make_pair(a,b);
}

inline int mult(ll a,ll b)
{
	return (a*b)%MOD;
}

inline int pot(int n,int k)
{
	if (k==0) return 1;
	ll a=pot(n,k/2);
	a=mult(a,a);
	if (k%2) return mult(a,n);
	else return a;
}

int divide(int a,int b)
{
	return mult(a,pot(b,MOD-2));
}

inline int sub(int a,int b)
{
	if (a-b>=0) return a-b;
	return a-b+MOD;
}

inline int add(int a,int b)
{
	if (a+b>=MOD) return a+b-MOD;
	return a+b;
}

bool prime(ll a)
{
	if (a==1) return 0;
	for (int i=2;i<=round(sqrt(a));++i)
	{
		if (a%i==0) return 0;
	}
	return 1;
}

ll has(string x)
{
	ll h1=0,h2=0;
	x=to_lower(x);
	for (char a: x)
	{
		h1*=bases[0];
		h1+=a-'a';
		h1%=bases[3];
		h2*=bases[1];
		h2+=a-'a';
		h2%=bases[4];
	}
	return h1*(MOD+13893829)+h2;
}

const int N=1010,M=1<<10,SZ=2907;
int n,fac[N],inf[N],dp[N],pre[N],in[N];
pii h[N];
vector<pii> ha[N][SZ];
vector<pii> so;
vector<int> poi;
set<int> poo;
int seg[M+N][N];
int po[N];
int dx[]={0,1,0,-1};
int dy[]={1,0,-1,0};

void addH(int i,int j,int x)
{
	int i1=i;
	i=(i^0x183b4278)%SZ;
	for (auto &a: ha[j][i]) if (a.y==i1)
	{
		a.x=add(a.x,x);
		return;
	}
	ha[j][i].pb({x,i1});
}

void upd(int i,int j,int x)
{
	i+=M;
	seg[i][j]=add(seg[i][j],x);
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	for (int i=0;i<10;++i) bases.push_back((rand()%MOD+13893829)%MOD);
	cin>>n;
	fac[0]=1;
	const int MAX=505;
	for (int i=1;i<=MAX;++i) fac[i]=mult(fac[i-1],i),in[i]=divide(1,i);
	inf[MAX]=divide(1,fac[MAX]);
	for (int i=MAX-1;i>=0;--i) inf[i]=mult(inf[i+1],i+1);
	for (int i=0;i<n;++i) cin>>h[i].x>>h[i].y,poo.insert(h[i].x),poo.insert(h[i].y+1);
	for (auto a: poo) poi.pb(a);
	for (int i=1;i<poi.size();++i) so.pb({poi[i-1],poi[i]});
	so.pb({poi.back(),MOD-6});
	upd(0,0,1);
	for (int k=0;k<=MAX;++k) pre[k]+=1;
	dp[0]=1;
	for (int i=0;i<n;++i)
	{
		for (int j=upper_bound(so.begin(),so.end(),mp(h[i].y+1,0))-so.begin()-1;j>=0 && so[j].x>=h[i].x;--j)
		{
			int jj=j+1;
			for (int k=MAX-1;k>=0;--k) upd(jj,k+1,seg[jj+M][k]);
			//for (int k=MAX-1;k>=0;--k) upd(jj,k,-seg[jj+M][k+1]);
			for (int k=0;k<1;++k) upd(jj,k,pre[j]);
			//cout<<en<<i<<' '<<jj<<' '<<so[j].x<<' '<<so[j].y;
			int re=0,r1=1;
			for (int k=0;k<min(MAX,so[j].y-so[j].x);++k)
			{
				r1=mult(r1,so[j].y-so[j].x-k);
				r1=mult(r1,in[k+1]);
				re=add(re,mult(r1,seg[jj+M][k]));
			}
			for (int k=jj;k<=MAX*2;++k) pre[k]=add(pre[k],sub(re,dp[jj]));
			dp[jj]=re;
			//cout<<' '<<re<<endl;
			//cout<<i<<' '<<j<<' '<<so[j].x<<' '<<so[j].y<<endl;
			//for (int k=0;k<MAX;++k) cout<<seg[jj+M][k]<<' ';
			//cout<<endl<<en<<endl;
			//upd(j+1,mult(get(0,j+1),so[j].y-so[j].x));
		}
	}
	int res=0;
	for (int i=1;i<=so.size();++i) for (int k=0;k<min(MAX,so[i-1].y-so[i-1].x);++k) if (1)
	{
		int r1=1;
		for (int j=so[i-1].y-so[i-1].x;j>=so[i-1].y-so[i-1].x-k;--j) r1=mult(r1,j);
		r1=mult(r1,inf[k+1]);
		r1=mult(r1,seg[i+M][k]);
		//if (r1) cout<<i<<' '<<k<<' '<<r1<<endl;
		res=add(res,r1);
	}
	cout<<res;
}

Compilation message (stderr)

boat.cpp: In function 'int main()':
boat.cpp:229:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=1;i<poi.size();++i) so.pb({poi[i-1],poi[i]});
               ~^~~~~~~~~~~
boat.cpp:260:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=1;i<=so.size();++i) for (int k=0;k<min(MAX,so[i-1].y-so[i-1].x);++k) if (1)
               ~^~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 22
• Subtask 3: 27 / 27
• Subtask 4: 0 / 42