Submission #117860

#	Time	Username	Problem	Language	Result	Execution time	Memory
117860		ckodser	Boat (APIO16_boat)	C++14	100 / 100	1115 ms	8756 KiB

boat

#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

int gcd(int a, int b) {return b == 0 ? a : gcd(b, a % b);}

#define ll int
#define pb push_back
#define ld long double
#define mp make_pair
#define F first
#define S second
#define pii pair<ll,ll> 

using namespace :: std;

const ll maxn=590;
const ll mod=1e9+7;
const ll inf=1e9+9;


inline void zarb(ll &a,long long  b){a=((long long)a*b)%mod;}
inline ll zarbO(long long a,long long b){return (a*b)%mod;}
inline void jam(ll &a,ll b){a+=b;if(a>=mod)a-=mod;}
inline ll jamO(ll a,ll b){a+=b;if(a>=mod)a-=mod;return a;}




ll dp[maxn][maxn*2];
ll dppar[maxn][maxn*2];
ll f[maxn*2][maxn];
ll ent[maxn][maxn];


ll rev[maxn];
ll a[maxn];
ll b[maxn];

ll poww(ll a,ll b){
	ll ans=1;
	while(b){
		if(b&1){
			zarb(ans,a);
		}
		b>>=1;
		zarb(a,a);
	}
	return ans;
}	


ll tmp[maxn];
void hesab(ll x,ll tol){
	if(tol==1){
		for(ll t=0;t+1<maxn;t++){
			f[x][t]=1;
		}
		return ;
	}		
	tmp[0]=1;
	for(ll i=1;i<maxn;i++){
		tmp[i]=zarbO(tmp[i-1],zarbO(tol-i+1,rev[i]));
	}
	for(ll t=0;t+1<maxn;t++){
		for(ll i=0;i<=t;i++){
			jam(f[x][t],zarbO(ent[t][i],tmp[i+1]));
		}
	}
}
int main(){
	for(ll i=0;i<maxn;i++){
		rev[i]=poww(i,mod-2);
	}	
	ent[0][0]=1;
	for(ll i=1;i<maxn;i++){
		ent[i][0]=1;
		ent[i][i]=1;
		for(ll j=1;j<i;j++){
			ent[i][j]=jamO(ent[i-1][j],ent[i-1][j-1]);
		}
	}
	ll n;
	cin>>n;
	vector<ll> vec;
	vec.pb(0);
	vec.pb(inf);
	for(ll i=0;i<n;i++){
		cin>>a[i]>>b[i];
		vec.pb(a[i]);
		vec.pb(b[i]+1);
	}
	{
		sort(vec.begin(),vec.end());
		auto it=unique(vec.begin(),vec.end());
		vec.resize(it-vec.begin());
	}
	for(ll i=0;i+1<(ll)vec.size();i++){
		ll tol=vec[i+1]-vec[i];
		hesab(i,tol);
	}
	ll ans=0;
	for(ll i=0;i<n;i++){
		for(ll j=0;j+1<(ll)vec.size();j++){
			//dp[i][j];
			if(a[i]<=vec[j] && b[i]+1>=vec[j+1]){
				ll tol=vec[j+1]-vec[j];
				ll tedad=0;
				for(ll z=i-1;z>=0;z--){
					if(j)jam(dp[i][j],zarbO(dppar[z][j-1],f[j][tedad]));
					tedad+=(a[z]<=vec[j] && b[z]+1>=vec[j+1]);	
				}
				jam(dp[i][j],f[j][tedad]);
			}
		}
		dppar[i][0]=dp[i][0];
		for(ll j=1;j+1<(ll)vec.size();j++){
			dppar[i][j]=jamO(dppar[i][j-1],dp[i][j]);
		}
		jam(ans,dppar[i][vec.size()-2]);
	}
	cout<<ans;
}

Compilation message (stderr)

boat.cpp: In function 'int main()':
boat.cpp:157:8: warning: unused variable 'tol' [-Wunused-variable]
     ll tol=vec[j+1]-vec[j];
        ^~~

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