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Submission #579354

# Submission time Handle Problem Language Result Execution time Memory
579354 2022-06-19T02:59:21 Z jiahng Boat (APIO16_boat) C++14
9 / 100
 2000 ms 17328 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 f(int x,int y){
	int ans = 0;
	FOR(z,1,x){
		ans += nck(x-1,z-1) * specnck(y,z);
	}
	return 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());
	
	vpi ranges;
	FOR(i,0,(int)v.size()-1){
        ranges.pb(pi(v[i],1));
        if (i + 1 < (int)v.size() && v[i] + 1 < v[i+1]) ranges.pb(pi(i+1,v[i+1]-v[i]-1));
    }

    FOR(i,0,(int)ranges.size()-1){
        S[i] = ranges[i].f; E[i] = ranges[i].f + ranges[i].s - 1;
    }
    
    FOR(i,0,(int)ranges.size()-1){
		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,0,(int)ranges.size()-1) dp[N+1][i] = 1;
    DEC(i,N,1){
		DEC(j,(int)ranges.size()-1,0){
			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][0]) %= MOD;
	}
    cout << ans;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 14188 KB Output is correct
2 Correct 17 ms 14164 KB Output is correct
3 Correct 14 ms 14156 KB Output is correct
4 Correct 13 ms 14160 KB Output is correct
5 Correct 12 ms 14224 KB Output is correct
6 Correct 12 ms 14164 KB Output is correct
7 Correct 11 ms 14164 KB Output is correct
8 Correct 11 ms 14160 KB Output is correct
9 Correct 11 ms 14164 KB Output is correct
10 Correct 11 ms 14164 KB Output is correct
11 Correct 12 ms 14164 KB Output is correct
12 Correct 14 ms 14164 KB Output is correct
13 Correct 16 ms 14164 KB Output is correct
14 Correct 15 ms 14256 KB Output is correct
15 Correct 15 ms 14156 KB Output is correct
16 Correct 7 ms 4436 KB Output is correct
17 Correct 7 ms 4624 KB Output is correct
18 Correct 7 ms 4564 KB Output is correct
19 Correct 9 ms 4636 KB Output is correct
20 Correct 8 ms 4564 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 14188 KB Output is correct
2 Correct 17 ms 14164 KB Output is correct
3 Correct 14 ms 14156 KB Output is correct
4 Correct 13 ms 14160 KB Output is correct
5 Correct 12 ms 14224 KB Output is correct
6 Correct 12 ms 14164 KB Output is correct
7 Correct 11 ms 14164 KB Output is correct
8 Correct 11 ms 14160 KB Output is correct
9 Correct 11 ms 14164 KB Output is correct
10 Correct 11 ms 14164 KB Output is correct
11 Correct 12 ms 14164 KB Output is correct
12 Correct 14 ms 14164 KB Output is correct
13 Correct 16 ms 14164 KB Output is correct
14 Correct 15 ms 14256 KB Output is correct
15 Correct 15 ms 14156 KB Output is correct
16 Correct 7 ms 4436 KB Output is correct
17 Correct 7 ms 4624 KB Output is correct
18 Correct 7 ms 4564 KB Output is correct
19 Correct 9 ms 4636 KB Output is correct
20 Correct 8 ms 4564 KB Output is correct
21 Execution timed out 2082 ms 17328 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 42 ms 2972 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 14188 KB Output is correct
2 Correct 17 ms 14164 KB Output is correct
3 Correct 14 ms 14156 KB Output is correct
4 Correct 13 ms 14160 KB Output is correct
5 Correct 12 ms 14224 KB Output is correct
6 Correct 12 ms 14164 KB Output is correct
7 Correct 11 ms 14164 KB Output is correct
8 Correct 11 ms 14160 KB Output is correct
9 Correct 11 ms 14164 KB Output is correct
10 Correct 11 ms 14164 KB Output is correct
11 Correct 12 ms 14164 KB Output is correct
12 Correct 14 ms 14164 KB Output is correct
13 Correct 16 ms 14164 KB Output is correct
14 Correct 15 ms 14256 KB Output is correct
15 Correct 15 ms 14156 KB Output is correct
16 Correct 7 ms 4436 KB Output is correct
17 Correct 7 ms 4624 KB Output is correct
18 Correct 7 ms 4564 KB Output is correct
19 Correct 9 ms 4636 KB Output is correct
20 Correct 8 ms 4564 KB Output is correct
21 Execution timed out 2082 ms 17328 KB Time limit exceeded
22 Halted 0 ms 0 KB -