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Submission #579361

# Submission time Handle Problem Language Result Execution time Memory
579361 2022-06-19T03:05:33 Z jiahng Boat (APIO16_boat) C++14
9 / 100
 817 ms 29412 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define int ll
typedef pair<int32_t, int32_t> pi;
typedef vector <int> vi;
typedef vector <pi> vpi;
typedef pair<pi, ll> pii;
typedef set <ll> si;
typedef long double ld;
#define f first
#define s second
#define mp make_pair
#define FOR(i,s,e) for(int i=s;i<=int(e);++i)
#define DEC(i,s,e) for(int i=s;i>=int(e);--i)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lbd(x, y) lower_bound(all(x), y)
#define ubd(x, y) upper_bound(all(x), y)
#define aFOR(i,x) for (auto i: x)
#define mem(x,i) memset(x,i,sizeof x)
#define fast ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define maxn 1010
#define INF (ll)1e9+10
#define MOD 1000000007
typedef pair <vi, int> pvi;
typedef pair <int,pi> ipi;
typedef vector <pii> vpii;
int N,A[maxn],B[maxn];
int fac[maxn], invfac[maxn];
int qexp(int a,int b){
    int ans = 1;
    while (b){
        if (b&1) (ans *= a) %= MOD;
        (a *= a) %= MOD;
        b >>= 1;
    }
    return ans;
}
int nck(int n,int k){
    if (k > n) return 0;
    return (((fac[n] * invfac[k]) % MOD) * invfac[n-k]) % MOD;
}
int suffmult[2*maxn][maxn];
int dp[maxn][2*maxn];
int S[2*maxn],E[2*maxn];
int specnck(int x,int k){
	//~ cout << E[x]-S[x]+1 << ' ' << k << ' ' << (invfac[k] * suffmult[x][k]) % MOD << '\n';
	return (invfac[k] * suffmult[x][k]) % MOD;
}

int memo[maxn][maxn];
int f(int x,int y){
	if (memo[x][y] != -1) return memo[x][y];
	int ans = 0;
	FOR(z,1,x){
		ans += nck(x-1,z-1) * specnck(y,z);
	}
	return memo[x][y] = ans;
}
int32_t main(){
    cin >> N;
    FOR(i,1,N) cin >> A[i] >> B[i];
    fac[0] = 1;
    FOR(i,1,N) fac[i] = (fac[i-1] * i) % MOD;
    invfac[N] = qexp(fac[N], MOD-2);
    DEC(i,N-1,0) invfac[i] = (invfac[i+1] * (i+1)) % MOD;
    vi v;
    FOR(i,1,N){
		v.pb(A[i]); v.pb(B[i]);
	}
	v.pb(0); v.pb(INF);
    sort(all(v)); v.erase(unique(all(v)),v.end());
	
	int M = 1;
	FOR(i,0,(int)v.size()-1){
		S[M] = v[i]; E[M] = v[i];
		M++;
        if (i + 1 < (int)v.size() && v[i] + 1 < v[i+1]){
			S[M] = v[i]+1; E[M] = v[i+1]-1; M++;
		}
    }
	M--;
    
    FOR(i,1,M){
		suffmult[i][0] = 1;
		int x = E[i] - S[i] + 1;
		FOR(j,1,N){
			suffmult[i][j] = (suffmult[i][j-1] * x) % MOD;
			x--;
		}
	}
    FOR(i,1,M+1) dp[N+1][i] = 1;
    mem(memo, -1);
    DEC(i,N,1){
		DEC(j,M,1){
			if (B[i] < S[j]){
				dp[i][j] = 0; continue;
			}
			dp[i][j] = dp[i][j+1];
			
			if (A[i] <= S[j] && E[j] <= B[i]){
				int num = 1;
				FOR(k,i+1,N+1){
					(dp[i][j] += (dp[k][j+1] * f(num, j)) % MOD) %= MOD;
					if (A[k] <= S[j] && E[j] <= B[k]) num++;
					
				}
			}
				
		}
    }
	int ans = 0;
	FOR(i,1,N){
		(ans += dp[i][1]) %= MOD;
	}
    cout << ans;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 22100 KB Output is correct
2 Correct 13 ms 22144 KB Output is correct
3 Correct 17 ms 22100 KB Output is correct
4 Correct 14 ms 22120 KB Output is correct
5 Correct 14 ms 22156 KB Output is correct
6 Correct 13 ms 22204 KB Output is correct
7 Correct 13 ms 22212 KB Output is correct
8 Correct 12 ms 22140 KB Output is correct
9 Correct 13 ms 22100 KB Output is correct
10 Correct 13 ms 22100 KB Output is correct
11 Correct 14 ms 22100 KB Output is correct
12 Correct 18 ms 22112 KB Output is correct
13 Correct 17 ms 22100 KB Output is correct
14 Correct 17 ms 22196 KB Output is correct
15 Correct 14 ms 22100 KB Output is correct
16 Correct 7 ms 12464 KB Output is correct
17 Correct 7 ms 12628 KB Output is correct
18 Correct 8 ms 12500 KB Output is correct
19 Correct 7 ms 12628 KB Output is correct
20 Correct 8 ms 12468 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 22100 KB Output is correct
2 Correct 13 ms 22144 KB Output is correct
3 Correct 17 ms 22100 KB Output is correct
4 Correct 14 ms 22120 KB Output is correct
5 Correct 14 ms 22156 KB Output is correct
6 Correct 13 ms 22204 KB Output is correct
7 Correct 13 ms 22212 KB Output is correct
8 Correct 12 ms 22140 KB Output is correct
9 Correct 13 ms 22100 KB Output is correct
10 Correct 13 ms 22100 KB Output is correct
11 Correct 14 ms 22100 KB Output is correct
12 Correct 18 ms 22112 KB Output is correct
13 Correct 17 ms 22100 KB Output is correct
14 Correct 17 ms 22196 KB Output is correct
15 Correct 14 ms 22100 KB Output is correct
16 Correct 7 ms 12464 KB Output is correct
17 Correct 7 ms 12628 KB Output is correct
18 Correct 8 ms 12500 KB Output is correct
19 Correct 7 ms 12628 KB Output is correct
20 Correct 8 ms 12468 KB Output is correct
21 Incorrect 817 ms 29412 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 15 ms 10964 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 22100 KB Output is correct
2 Correct 13 ms 22144 KB Output is correct
3 Correct 17 ms 22100 KB Output is correct
4 Correct 14 ms 22120 KB Output is correct
5 Correct 14 ms 22156 KB Output is correct
6 Correct 13 ms 22204 KB Output is correct
7 Correct 13 ms 22212 KB Output is correct
8 Correct 12 ms 22140 KB Output is correct
9 Correct 13 ms 22100 KB Output is correct
10 Correct 13 ms 22100 KB Output is correct
11 Correct 14 ms 22100 KB Output is correct
12 Correct 18 ms 22112 KB Output is correct
13 Correct 17 ms 22100 KB Output is correct
14 Correct 17 ms 22196 KB Output is correct
15 Correct 14 ms 22100 KB Output is correct
16 Correct 7 ms 12464 KB Output is correct
17 Correct 7 ms 12628 KB Output is correct
18 Correct 8 ms 12500 KB Output is correct
19 Correct 7 ms 12628 KB Output is correct
20 Correct 8 ms 12468 KB Output is correct
21 Incorrect 817 ms 29412 KB Output isn't correct
22 Halted 0 ms 0 KB -