제출 #1132578

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1132578		t9unkubj	Boat (APIO16_boat)	C++20	100 / 100	585 ms	6524 KiB

boat

#ifdef t9unkubj

#define _GLIBCXX_DEBUG
#include"debug.cpp"
//#include"template_no_debug.h"
#else 
#define dbg(...) 199958
#endif

#pragma GCC optimize("O3")
using namespace std;
#include<bits/stdc++.h>
using ll=long long;
using ull=unsigned long long;
template<class T>using vc=vector<T>;
template<class T>using vvc=vc<vc<T>>;
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define REP(i,j,n) for(ll i=(j);i<(ll)(n);i++)
#define DREP(i,n,m) for(ll i=(n);i>=(m);i--)
#define drep(i,n) for(ll i=((n)-1);i>=0;i--)
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
template<class T,class F>
bool chmin(T &x, F y){
    if(x>y){
        x=y;
        return true;
    }
    return false;
}
template<class T, class F>
bool chmax(T &x, F y){
    if(x<y){
        x=y;
        return true;
    }
    return false;
}
double pass_time=0;
template<class T,class G,class F>
F modpow(T x,G p,F m){
    T ret=1%m;
    x%=m;
    while(p){
        if(p&1)ret=(1ll*ret*x)%m;
        x=(1ll*x*x)%m;
        p>>=1;
    }
    return ret;
}
template<class T>
T extgcd(T a,T b,T&x,T&y){//ax+by=gcd(a,b)となるようなもの
    if(b==0){
        x=1;
        y=0;
        return a;
    }else{
        T res=extgcd(b,a%b,y,x);
        y-=(a/b)*x;
        return res;
    }
}
template<class T>
pair<T,T> inv(T x,T m){
    T a1,a2;
    T res=extgcd(x,m,a1,a2);
    return {a1,m/res};
}
constexpr int mod=1e9+7;
struct mint{
    int val;
    inline long long fast(long long x){
        if(x<mod&&x>=0)return x;
        x%=mod;
        if(x<0)x+=mod;
        return x;
    }
    mint():val(0){}
    mint(long long val):val(fast(val)){}
    mint power(long long m)const {
        mint res(1);
        mint ret(*this);
        while(m){
           if(m&1)res*=ret;
           ret*=ret;
           m>>=1;
        }
        return res;
    }
    mint& operator++() {
        val++;
        if (val == mod) val = 0;
        return *this;
    }
    mint& operator--() {
        if (val == 0)val=mod;
        val--;
        return *this;
    }
    mint operator++(int) {
        mint result = *this;
        ++*this;
        return result;
    }
    mint operator--(int) {
        mint result = *this;
        --*this;
        return result;
    }
    mint operator-() const { 
      return mint(-val);
    }
    friend mint operator +(const mint&a,const mint&b) noexcept{
        return mint(a)+=b;
    }
    friend mint operator -(const mint&a,const mint&b) noexcept{
        return mint(a)-=b;
    }
    friend mint operator *(const mint&a,const mint&b) noexcept{
        return mint(a)*=b;
    }
    friend mint operator /(const mint&a,const mint&b) noexcept{
        return mint(a)/=b;
    }
    mint& operator+=(const mint&a)noexcept{
        val+=a.val;
        if(val>=mod)val-=mod;
        return *this;
    }
    mint& operator-=(const mint&a)noexcept{
        val-=a.val;
        if(val<0)val+=mod;
        return *this;
    }
    mint& operator*=(const mint&a){
        val=fast(1ll*val*a.val);
        return *this;
    }
    mint& operator/=(const mint&a){
        val=fast(1ll*val*inv<long long>(a.val,mod).first);
        return *this;
    }
    bool operator == (const mint&x)const noexcept{
        return this->val==x.val;
    }
    bool operator != (const mint&x)const noexcept{
        return this->val!=x.val;
    }
    friend ostream& operator << (ostream &os, const mint &x) noexcept {
        return os << x.val;
    }
    friend istream& operator >> (istream &is,  mint &x) noexcept {
        long long v;
        is >> v;
        x=mint(v);
        return is;
    }
};
vector<mint>fact(1,1),invfact(1,1);
void build(int n){
    if(n<(int)fact.size())return;
    fact=invfact=vector<mint>(n+1);
    fact[0]=1;
    for(int i=1;i<=n;i++)fact[i]=fact[i-1]*i;
    invfact[n]=(1/fact[n]);
    for(int i=n-1;i>=0;i--)invfact[i]=invfact[i+1]*(i+1);
}
mint C(int a,int b){//aCb
    if(a<0||b<0||a-b<0)return mint(0);
    while((int)fact.size()<=a){
        fact.push_back(fact.back()*(fact.size()));
    }
    while((int)invfact.size()<=a){
        invfact.push_back(invfact.back()/invfact.size());
    }
    return fact[a]*invfact[b]*invfact[a-b];
}
mint P(int a,int b){
    if(a<b||b<0)return 0;
    return fact[a]*invfact[a-b];
}
//a個のものからb個を重複を許して選ぶ
mint H(int a,int b){
    return C(a+b-1,b);
}
void print(mint a) { cout << a; }
template<class T>
pair<T,T> mod_solve(T a,T b,T m){//ax=b mod mとなるxを返す
    a%=m,b%=m;if(a<0)a+=m;if(b<0)b+=m;
    T g=gcd(gcd(a,b),m);
    a/=g,b/=g,m/=g;
    if(gcd(a,m)>1)return {-1,-1};
    return {(inv(a,m).first*b)%m,inv(a,m).second};
}
/*
dp[i][j][l]:=i番目までみて現在j区画目をl人が見ている
*/
vvc<pair<int,int>> brute(int n,vc<int>a,vc<int>b){
    vvc<pair<int,int>>ans;
    REP(i,1,1<<n){
        vc<int>is;
        vc<pair<int,int>>f{{-1,-1}};
        rep(j,n)if(i>>j&1)is.push_back(j);
        auto dfs=[&](auto&dfs,int I,vc<pair<int,int>>pres)->void{
            
            if(I==is.size()){   
                ans.push_back(pres);
                return;
            }
            int i=is[I];
            REP(j,a[i],b[i]+1){
                if(j>pres.back().first){
                    pres.push_back({j,i});
                    dfs(dfs,I+1,pres);
                    pres.pop_back();
                }
            }
        };
        dfs(dfs,0,f);
    }
    return ans;
}
int solve(int n,vc<int>a,vc<int>b){
    map<int,int>ma;
    rep(i,n)ma[a[i]]=0;
    rep(i,n)ma[b[i]+1]=0;
    int id=0;

    ma[-1]=0;
    for(auto&[x,y]:ma)y=id++;

    int c=ma.size()-1;
    vc<int>len(c);
    for(auto&[x,y]:ma){
        if(y<c)len[y]-=x;
        if(y)len[y-1]+=x;
    }
    len[0]=0;

    vvc<mint>comb(c,vc<mint>(n+1));
    rep(i,c){
        comb[i][0]=1;
        rep(j,n){
            //C(len[i],j) to C(len[i],j+1)
            comb[i][j+1]=comb[i][j]*(len[i]-j)/mint(j+1);
        }
    }

    vvc<mint>dp(c+1,vc<mint>(n+1));
    dp[0][0]=1;
    rep(i,n){
        vvc<mint>ndp=dp;
        int L=ma[a[i]],R=ma[b[i]+1];
        //[L,R)
        //segment 
        
        vc<mint>pre(i+1);
        REP(j,1,R){
            rep(l,i+1){
                pre[l]+=dp[j-1][l]*comb[j-1][l];
                if(j>=L)ndp[j][1]+=pre[l];
                if(j>=L)ndp[j][l+1]+=dp[j][l];
            }
        }
        dp=move(ndp);
    }

    mint ans=-1;
    rep(i,c)rep(j,n+1){
        ans+=dp[i][j]*comb[i][j];
    }
    
    return ans.val;
}
void run(){
    int n;
    cin>>n;
    vc<int>a(n),b(n);
    rep(i,n)cin>>a[i]>>b[i];
    cout<<solve(n,a,b)<<"\n";
}
signed main(){
#ifdef t9unkubj
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
    cin.tie(0)->sync_with_stdio(0);
    pass_time=clock();
    int t=1;
    //cin>>t;
    run();
    pass_time=clock()-pass_time;
    dbg(pass_time/CLOCKS_PER_SEC);
}

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