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Submission #579365

# Submission time Handle Problem Language Result Execution time Memory
579365 2022-06-19T03:09:59 Z jiahng Boat (APIO16_boat) C++14
36 / 100
 760 ms 31740 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 1110
#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)) % MOD) %= MOD;
	}
	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){
					(dp[i][j] += (dp[k][j+1] * f(num, j)) % MOD) %= MOD;
					if (A[k] <= S[j] && E[j] <= B[k]) num++;
				}
				(dp[i][j] += f(num, j)) %= MOD; // if no more > j segments
			}
				
		}
    }
	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 23832 KB Output is correct
2 Correct 16 ms 23868 KB Output is correct
3 Correct 18 ms 23892 KB Output is correct
4 Correct 16 ms 23908 KB Output is correct
5 Correct 16 ms 23836 KB Output is correct
6 Correct 16 ms 23852 KB Output is correct
7 Correct 15 ms 23892 KB Output is correct
8 Correct 15 ms 23892 KB Output is correct
9 Correct 16 ms 23860 KB Output is correct
10 Correct 14 ms 23912 KB Output is correct
11 Correct 14 ms 23892 KB Output is correct
12 Correct 16 ms 23892 KB Output is correct
13 Correct 14 ms 23892 KB Output is correct
14 Correct 16 ms 23900 KB Output is correct
15 Correct 14 ms 23920 KB Output is correct
16 Correct 8 ms 14036 KB Output is correct
17 Correct 8 ms 14292 KB Output is correct
18 Correct 8 ms 14164 KB Output is correct
19 Correct 9 ms 14292 KB Output is correct
20 Correct 9 ms 14164 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 23832 KB Output is correct
2 Correct 16 ms 23868 KB Output is correct
3 Correct 18 ms 23892 KB Output is correct
4 Correct 16 ms 23908 KB Output is correct
5 Correct 16 ms 23836 KB Output is correct
6 Correct 16 ms 23852 KB Output is correct
7 Correct 15 ms 23892 KB Output is correct
8 Correct 15 ms 23892 KB Output is correct
9 Correct 16 ms 23860 KB Output is correct
10 Correct 14 ms 23912 KB Output is correct
11 Correct 14 ms 23892 KB Output is correct
12 Correct 16 ms 23892 KB Output is correct
13 Correct 14 ms 23892 KB Output is correct
14 Correct 16 ms 23900 KB Output is correct
15 Correct 14 ms 23920 KB Output is correct
16 Correct 8 ms 14036 KB Output is correct
17 Correct 8 ms 14292 KB Output is correct
18 Correct 8 ms 14164 KB Output is correct
19 Correct 9 ms 14292 KB Output is correct
20 Correct 9 ms 14164 KB Output is correct
21 Incorrect 760 ms 31740 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 12628 KB Output is correct
2 Correct 11 ms 12628 KB Output is correct
3 Correct 13 ms 12568 KB Output is correct
4 Correct 13 ms 12600 KB Output is correct
5 Correct 15 ms 12612 KB Output is correct
6 Correct 19 ms 12628 KB Output is correct
7 Correct 18 ms 12536 KB Output is correct
8 Correct 19 ms 12596 KB Output is correct
9 Correct 18 ms 12628 KB Output is correct
10 Correct 19 ms 12552 KB Output is correct
11 Correct 14 ms 12628 KB Output is correct
12 Correct 12 ms 12536 KB Output is correct
13 Correct 14 ms 12588 KB Output is correct
14 Correct 13 ms 12636 KB Output is correct
15 Correct 13 ms 12628 KB Output is correct
16 Correct 9 ms 11348 KB Output is correct
17 Correct 9 ms 11316 KB Output is correct
18 Correct 8 ms 11304 KB Output is correct
19 Correct 8 ms 11316 KB Output is correct
20 Correct 8 ms 11348 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 23832 KB Output is correct
2 Correct 16 ms 23868 KB Output is correct
3 Correct 18 ms 23892 KB Output is correct
4 Correct 16 ms 23908 KB Output is correct
5 Correct 16 ms 23836 KB Output is correct
6 Correct 16 ms 23852 KB Output is correct
7 Correct 15 ms 23892 KB Output is correct
8 Correct 15 ms 23892 KB Output is correct
9 Correct 16 ms 23860 KB Output is correct
10 Correct 14 ms 23912 KB Output is correct
11 Correct 14 ms 23892 KB Output is correct
12 Correct 16 ms 23892 KB Output is correct
13 Correct 14 ms 23892 KB Output is correct
14 Correct 16 ms 23900 KB Output is correct
15 Correct 14 ms 23920 KB Output is correct
16 Correct 8 ms 14036 KB Output is correct
17 Correct 8 ms 14292 KB Output is correct
18 Correct 8 ms 14164 KB Output is correct
19 Correct 9 ms 14292 KB Output is correct
20 Correct 9 ms 14164 KB Output is correct
21 Incorrect 760 ms 31740 KB Output isn't correct
22 Halted 0 ms 0 KB -