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Submission #579366

# Submission time Handle Problem Language Result Execution time Memory
579366 2022-06-19T03:10:55 Z jiahng Boat (APIO16_boat) C++14
36 / 100
 18 ms 10360 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 510
#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 9 ms 10324 KB Output is correct
2 Correct 9 ms 10324 KB Output is correct
3 Correct 9 ms 10336 KB Output is correct
4 Correct 8 ms 10324 KB Output is correct
5 Correct 9 ms 10324 KB Output is correct
6 Correct 8 ms 10360 KB Output is correct
7 Correct 10 ms 10324 KB Output is correct
8 Correct 10 ms 10292 KB Output is correct
9 Correct 9 ms 10324 KB Output is correct
10 Correct 9 ms 10336 KB Output is correct
11 Correct 9 ms 10324 KB Output is correct
12 Correct 9 ms 10324 KB Output is correct
13 Correct 8 ms 10324 KB Output is correct
14 Correct 9 ms 10324 KB Output is correct
15 Correct 11 ms 10324 KB Output is correct
16 Correct 5 ms 5700 KB Output is correct
17 Correct 4 ms 5844 KB Output is correct
18 Correct 4 ms 5844 KB Output is correct
19 Correct 4 ms 5884 KB Output is correct
20 Correct 5 ms 5844 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 10324 KB Output is correct
2 Correct 9 ms 10324 KB Output is correct
3 Correct 9 ms 10336 KB Output is correct
4 Correct 8 ms 10324 KB Output is correct
5 Correct 9 ms 10324 KB Output is correct
6 Correct 8 ms 10360 KB Output is correct
7 Correct 10 ms 10324 KB Output is correct
8 Correct 10 ms 10292 KB Output is correct
9 Correct 9 ms 10324 KB Output is correct
10 Correct 9 ms 10336 KB Output is correct
11 Correct 9 ms 10324 KB Output is correct
12 Correct 9 ms 10324 KB Output is correct
13 Correct 8 ms 10324 KB Output is correct
14 Correct 9 ms 10324 KB Output is correct
15 Correct 11 ms 10324 KB Output is correct
16 Correct 5 ms 5700 KB Output is correct
17 Correct 4 ms 5844 KB Output is correct
18 Correct 4 ms 5844 KB Output is correct
19 Correct 4 ms 5884 KB Output is correct
20 Correct 5 ms 5844 KB Output is correct
21 Runtime error 9 ms 8896 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 4564 KB Output is correct
2 Correct 9 ms 4564 KB Output is correct
3 Correct 10 ms 4564 KB Output is correct
4 Correct 9 ms 4564 KB Output is correct
5 Correct 10 ms 4640 KB Output is correct
6 Correct 15 ms 4568 KB Output is correct
7 Correct 14 ms 4652 KB Output is correct
8 Correct 15 ms 4604 KB Output is correct
9 Correct 14 ms 4564 KB Output is correct
10 Correct 18 ms 4656 KB Output is correct
11 Correct 10 ms 4596 KB Output is correct
12 Correct 10 ms 4564 KB Output is correct
13 Correct 11 ms 4564 KB Output is correct
14 Correct 11 ms 4564 KB Output is correct
15 Correct 11 ms 4564 KB Output is correct
16 Correct 6 ms 3540 KB Output is correct
17 Correct 5 ms 3668 KB Output is correct
18 Correct 4 ms 3540 KB Output is correct
19 Correct 5 ms 3540 KB Output is correct
20 Correct 6 ms 3668 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 10324 KB Output is correct
2 Correct 9 ms 10324 KB Output is correct
3 Correct 9 ms 10336 KB Output is correct
4 Correct 8 ms 10324 KB Output is correct
5 Correct 9 ms 10324 KB Output is correct
6 Correct 8 ms 10360 KB Output is correct
7 Correct 10 ms 10324 KB Output is correct
8 Correct 10 ms 10292 KB Output is correct
9 Correct 9 ms 10324 KB Output is correct
10 Correct 9 ms 10336 KB Output is correct
11 Correct 9 ms 10324 KB Output is correct
12 Correct 9 ms 10324 KB Output is correct
13 Correct 8 ms 10324 KB Output is correct
14 Correct 9 ms 10324 KB Output is correct
15 Correct 11 ms 10324 KB Output is correct
16 Correct 5 ms 5700 KB Output is correct
17 Correct 4 ms 5844 KB Output is correct
18 Correct 4 ms 5844 KB Output is correct
19 Correct 4 ms 5884 KB Output is correct
20 Correct 5 ms 5844 KB Output is correct
21 Runtime error 9 ms 8896 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -