Submission #337787

#	Time	Username	Problem	Language	Result	Execution time	Memory
337787		talant117408	Energetic turtle (IZhO11_turtle)	C++17	5 / 100	93 ms	9836 KiB

turtle

/*
    Code written by Talant I.D.
*/
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
 
//using namespace __gnu_pbds;
using namespace std;
 
//typedef tree <int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
  
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
  
inline bool isvowel(char ch){
    ch = tolower(ch);
    return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u');
}
  
inline bool isprime(int n){
    if(n < 2 || (n%2 == 0 && n != 2)) return false;
    for(int i = 3; i*i <= n; i++)
        if(n%i == 0) return false;
    return true;
}
 
class Union{
    private:
        vector <int> saizu, link;
    public:
        Union(int n){
            saizu.assign(n, 1); link.resize(n); 
            iota(all(link), 0);
        }
        int find(int n){
            if(link[n] == n) return n;
            return link[n] = find(link[n]);
        }
        int same(int a, int b){
            return find(a) == find(b);
        }
        void unite(int a, int b){
            if(same(a, b)) return;
             
            a = find(a); b = find(b);
            if(saizu[a] < saizu[b]) swap(a, b);
             
            saizu[a] += saizu[b];
            link[b] = a;
        }
        int getsize(int a){
            return saizu[find(a)];
        }
};
 
const int mod = 1e9+7;
 
ll mode(ll a){
    a %= mod;
    if(a < 0) a += mod;
    return a;
}
 
ll subt(ll a, ll b){
    return mode(mode(a)-mode(b));
}
 
ll add(ll a, ll b){
    return mode(mode(a)+mode(b));
}
 
ll mult(ll a, ll b){
    return mode(mode(a)*mode(b));
}
 
ll binpow(ll a, ll b){
    ll res = 1;
    while(b){
        if(b&1) res = mult(res, a);
        a = mult(a, a);
        b >>= 1;
    }
    return res;
}

ll n, m, N, t, z;
ll dp[23][23];

bool cmp(pll a, pll b){
    return a.first+a.second < b.first+b.second;
}

ll fact[600007], rever[600007];

ll C(ll n, ll k){
    return mult(fact[n], mult(rever[k], rever[n-k]));
}

int main(){
    do_not_disturb
    
    fact[0] = rever[0] = 1;
    for(ll i = 1; i < 600007; i++){
        fact[i] = mult(fact[i-1], i);
        rever[i] = binpow(fact[i], mod-2);
    }
    
    cin >> n >> m >> N >> t >> z;
    vector <pll> v(N);
    for(auto &to : v) cin >> to.first >> to.second;
    v.pb(mp(n, m));
    sort(all(v), cmp);
    
    for(int times = 0; times <= t; times++){
        for(int i = 0; i <= N; i++){
            dp[i][times] = C(v[i].first+v[i].second, v[i].first);
            for(int j = 0; j < i; j++){
                if(v[j].first <= v[i].first && v[j].second <= v[i].second){
                    if(i == N)
                        dp[i][times] = subt(dp[i][times], dp[j][times]);
                    else
                    dp[i][times] = subt(dp[i][times], dp[j][times-1]);
                }
            }
        }
    }
    ll ans = 0;
    for(int times = 0; times <= t; times++){
        ans =  add(ans, dp[N][times]);
    }
    cout << ans;
    
    return 0;
}

• Subtask 1: 5 / 100