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Submission #390621

# Submission time Handle Problem Language Result Execution time Memory
390621 2021-04-16T12:15:11 Z Blagojce Boat (APIO16_boat) C++11
9 / 100
 2000 ms 384 KB 
#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define pb push_back
#define st first
#define nd second
#define pq priority_queue
#define all(x) begin(x), end(x)


using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int i_inf = 1e9;
const ll inf = 1e10;
const ll mod = 1e9+7;
const ld eps = 1e-13;
const ld pi  = 3.14159265359;

mt19937 _rand(time(NULL));
clock_t z;

const int mxn = 1000;


ll modpow(ll x, ll n){
	if(n == 0) return 1%mod;
	ll u = modpow(x, n/2);
	u = (u * u) % mod;
	if(n % 2) u = (u * x) % mod;
	return u;
}
ll inverse(ll x){
	return modpow(x, mod-2);
}

ll fakt[mxn];
ll bc1(ll n, ll k){
	if(n < k) return inverse(0);
	return (fakt[n]*inverse((fakt[k]*fakt[n-k])%mod))%mod;
}
ll bc2(ll n, ll k){
	if(n < k) return 0;
	
	
	ll ret = 1;
	fr(i, 0, k){
		ret *= (n-i);
		ret %= mod;
	}
	ret *= inverse(fakt[k]);
	ret %= mod;
	return ret;
}


int n;
ll l[mxn], r[mxn];

int DP1[mxn];
int DP2[mxn];


void solve(){
	fakt[0] = 1;
	fr(i, 1, mxn){
		fakt[i] = (fakt[i-1]*i)%mod;
	}
	
	cin >> n;
	fr(i, 0, n){
		cin >> l[i] >> r[i];
	}
	
	vector<pair<int,int> > v;
	fr(i, 0, n){
		v.pb({l[i], -i});
		v.pb({r[i],i+1});
	}
	
	sort(all(v));
	
	vector<int> active;
	
	DP1[0] = 1;
	
	ll prv = 0;
	
	ll a_len;
	
	for(auto u : v){
		
		
		int id = u.nd;
		
		if(id > 0){
			a_len = u.st - prv;
		}
		else{
			a_len = u.st - prv-1;
		}
				
		fr(i, 0, mxn) DP2[i] = DP1[i];
		
		
		
		
		fr(i, 0, (int)active.size()){
			ll sum = 0;
			fr(k, 0, active[i]+1){
				sum += DP1[k];
				sum %= mod;
			}
			
			fr(j, i, (int)active.size()){
				int psz = 1 + (int)(i != j);
				
				
				fr(len, psz, j-i+2){
					ll ways = (bc2(a_len, len)*bc1(i-j+1-psz, len-psz))%mod;
					DP2[active[j]+1] += (ways*sum)%mod;
					DP2[active[j]+1] %= mod;
				}
			}
		}
		
		fr(i, 0, mxn){
			DP1[i] = DP2[i];
		}
		
		if(id <= 0){
			prv = u.st-1; 
			active.pb(-id);
			sort(all(active));
			
		}else{
			prv = u.st;
			active.erase(find(all(active), id-1));
			sort(all(active));
		}
		
		
	}
	ll ans = 0;
	fr(i, 0, n+1){
		ans += DP1[i];
		ans %= mod;
	}
	--ans;
	if(ans < 0) ans += mod;
	
	cout<<ans<<endl;
	
}

int main(){
	
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	solve();
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 340 KB Output is correct
2 Correct 4 ms 332 KB Output is correct
3 Correct 4 ms 332 KB Output is correct
4 Correct 4 ms 332 KB Output is correct
5 Correct 4 ms 332 KB Output is correct
6 Correct 4 ms 332 KB Output is correct
7 Correct 4 ms 340 KB Output is correct
8 Correct 4 ms 344 KB Output is correct
9 Correct 4 ms 332 KB Output is correct
10 Correct 4 ms 332 KB Output is correct
11 Correct 4 ms 332 KB Output is correct
12 Correct 4 ms 332 KB Output is correct
13 Correct 4 ms 332 KB Output is correct
14 Correct 4 ms 332 KB Output is correct
15 Correct 4 ms 332 KB Output is correct
16 Correct 17 ms 332 KB Output is correct
17 Correct 18 ms 380 KB Output is correct
18 Correct 17 ms 344 KB Output is correct
19 Correct 19 ms 384 KB Output is correct
20 Correct 17 ms 332 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 340 KB Output is correct
2 Correct 4 ms 332 KB Output is correct
3 Correct 4 ms 332 KB Output is correct
4 Correct 4 ms 332 KB Output is correct
5 Correct 4 ms 332 KB Output is correct
6 Correct 4 ms 332 KB Output is correct
7 Correct 4 ms 340 KB Output is correct
8 Correct 4 ms 344 KB Output is correct
9 Correct 4 ms 332 KB Output is correct
10 Correct 4 ms 332 KB Output is correct
11 Correct 4 ms 332 KB Output is correct
12 Correct 4 ms 332 KB Output is correct
13 Correct 4 ms 332 KB Output is correct
14 Correct 4 ms 332 KB Output is correct
15 Correct 4 ms 332 KB Output is correct
16 Correct 17 ms 332 KB Output is correct
17 Correct 18 ms 380 KB Output is correct
18 Correct 17 ms 344 KB Output is correct
19 Correct 19 ms 384 KB Output is correct
20 Correct 17 ms 332 KB Output is correct
21 Execution timed out 2084 ms 332 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 1082 ms 332 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 340 KB Output is correct
2 Correct 4 ms 332 KB Output is correct
3 Correct 4 ms 332 KB Output is correct
4 Correct 4 ms 332 KB Output is correct
5 Correct 4 ms 332 KB Output is correct
6 Correct 4 ms 332 KB Output is correct
7 Correct 4 ms 340 KB Output is correct
8 Correct 4 ms 344 KB Output is correct
9 Correct 4 ms 332 KB Output is correct
10 Correct 4 ms 332 KB Output is correct
11 Correct 4 ms 332 KB Output is correct
12 Correct 4 ms 332 KB Output is correct
13 Correct 4 ms 332 KB Output is correct
14 Correct 4 ms 332 KB Output is correct
15 Correct 4 ms 332 KB Output is correct
16 Correct 17 ms 332 KB Output is correct
17 Correct 18 ms 380 KB Output is correct
18 Correct 17 ms 344 KB Output is correct
19 Correct 19 ms 384 KB Output is correct
20 Correct 17 ms 332 KB Output is correct
21 Execution timed out 2084 ms 332 KB Time limit exceeded
22 Halted 0 ms 0 KB -