Submission #722837

#	Time	Username	Problem	Language	Result	Execution time	Memory
722837		n0sk1ll	Boat (APIO16_boat)	C++14	9 / 100	3 ms	340 KiB

boat

#include <bits/stdc++.h>

#define FAST ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);cerr.tie(0)
#define mp make_pair
#define xx first
#define yy second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define all(x) x.begin(),x.end()
#define ff(i,a,b) for (int i = a; i < b; i++)
#define fff(i,a,b) for (int i = a; i <= b; i++)
#define bff(i,a,b) for (int i = b-1; i >= a; i--)
#define bfff(i,a,b) for (int i = b; i >= a; i--)

using namespace std;
long double typedef ld;
unsigned int typedef ui;
long long int typedef li;
pair<int,int> typedef pii;
pair<li,li> typedef pli;
pair<ld,ld> typedef pld;
vector<vector<int>> typedef graph;
unsigned long long int typedef ull;
//const int mod = 998244353;
const int mod = 1000000007;







//Note to self: Check for overflow

int a[505],b[505];

int dp[1069];

int main()
{
    FAST;

    int n; cin>>n;
    fff(i,1,n) cin>>a[i]>>b[i];

    vector<int> kords;
    kords.pb(0);
    kords.pb(mod);
    fff(i,1,n) kords.pb(a[i]);
    fff(i,1,n) kords.pb(b[i]+1);
    sort(all(kords));
    kords.erase(unique(all(kords)),kords.end());

    dp[0]=1;

    fff(i,1,n)
    {
        int tsum=0;
        ff(x,0,(int)kords.size())
        {
            int stari=dp[x];
            if (a[i]<=kords[x] && kords[x]<=b[i]){
                (dp[x]+=(li)(kords[x+1]-kords[x])*tsum%mod)%=mod;
            }
            (tsum+=stari)%=mod;
        }

        //ff(x,0,(int)kords.size()) cout<<dp[x]<<" "; cout<<endl;
    }

    int ans=0;
    ff(x,1,(int)kords.size()) (ans+=dp[x])%=mod;
    cout<<ans<<"\n";
}

//Note to self: Check for overflow

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