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Submission #579355

# Submission time Handle Problem Language Result Execution time Memory
579355 2022-06-19T03:00:35 Z jiahng Boat (APIO16_boat) C++14
9 / 100
 2000 ms 16856 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(v[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 12 ms 14164 KB Output is correct
2 Correct 11 ms 14164 KB Output is correct
3 Correct 15 ms 14160 KB Output is correct
4 Correct 12 ms 14220 KB Output is correct
5 Correct 11 ms 14164 KB Output is correct
6 Correct 13 ms 14192 KB Output is correct
7 Correct 13 ms 14216 KB Output is correct
8 Correct 12 ms 14164 KB Output is correct
9 Correct 11 ms 14164 KB Output is correct
10 Correct 14 ms 14164 KB Output is correct
11 Correct 17 ms 14164 KB Output is correct
12 Correct 15 ms 14164 KB Output is correct
13 Correct 14 ms 14200 KB Output is correct
14 Correct 17 ms 14168 KB Output is correct
15 Correct 13 ms 14164 KB Output is correct
16 Correct 6 ms 4436 KB Output is correct
17 Correct 6 ms 4588 KB Output is correct
18 Correct 6 ms 4564 KB Output is correct
19 Correct 6 ms 4592 KB Output is correct
20 Correct 6 ms 4564 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 14164 KB Output is correct
2 Correct 11 ms 14164 KB Output is correct
3 Correct 15 ms 14160 KB Output is correct
4 Correct 12 ms 14220 KB Output is correct
5 Correct 11 ms 14164 KB Output is correct
6 Correct 13 ms 14192 KB Output is correct
7 Correct 13 ms 14216 KB Output is correct
8 Correct 12 ms 14164 KB Output is correct
9 Correct 11 ms 14164 KB Output is correct
10 Correct 14 ms 14164 KB Output is correct
11 Correct 17 ms 14164 KB Output is correct
12 Correct 15 ms 14164 KB Output is correct
13 Correct 14 ms 14200 KB Output is correct
14 Correct 17 ms 14168 KB Output is correct
15 Correct 13 ms 14164 KB Output is correct
16 Correct 6 ms 4436 KB Output is correct
17 Correct 6 ms 4588 KB Output is correct
18 Correct 6 ms 4564 KB Output is correct
19 Correct 6 ms 4592 KB Output is correct
20 Correct 6 ms 4564 KB Output is correct
21 Execution timed out 2066 ms 16856 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 66 ms 2920 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 14164 KB Output is correct
2 Correct 11 ms 14164 KB Output is correct
3 Correct 15 ms 14160 KB Output is correct
4 Correct 12 ms 14220 KB Output is correct
5 Correct 11 ms 14164 KB Output is correct
6 Correct 13 ms 14192 KB Output is correct
7 Correct 13 ms 14216 KB Output is correct
8 Correct 12 ms 14164 KB Output is correct
9 Correct 11 ms 14164 KB Output is correct
10 Correct 14 ms 14164 KB Output is correct
11 Correct 17 ms 14164 KB Output is correct
12 Correct 15 ms 14164 KB Output is correct
13 Correct 14 ms 14200 KB Output is correct
14 Correct 17 ms 14168 KB Output is correct
15 Correct 13 ms 14164 KB Output is correct
16 Correct 6 ms 4436 KB Output is correct
17 Correct 6 ms 4588 KB Output is correct
18 Correct 6 ms 4564 KB Output is correct
19 Correct 6 ms 4592 KB Output is correct
20 Correct 6 ms 4564 KB Output is correct
21 Execution timed out 2066 ms 16856 KB Time limit exceeded
22 Halted 0 ms 0 KB -