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Submission #579360

# Submission time Handle Problem Language Result Execution time Memory
579360 2022-06-19T03:04:36 Z jiahng Boat (APIO16_boat) C++14
9 / 100
 845 ms 29512 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) 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 16 ms 22228 KB Output is correct
2 Correct 17 ms 22152 KB Output is correct
3 Correct 15 ms 22144 KB Output is correct
4 Correct 17 ms 22120 KB Output is correct
5 Correct 14 ms 22228 KB Output is correct
6 Correct 13 ms 22228 KB Output is correct
7 Correct 13 ms 22228 KB Output is correct
8 Correct 13 ms 22112 KB Output is correct
9 Correct 14 ms 22228 KB Output is correct
10 Correct 17 ms 22228 KB Output is correct
11 Correct 13 ms 22228 KB Output is correct
12 Correct 13 ms 22172 KB Output is correct
13 Correct 13 ms 22228 KB Output is correct
14 Correct 13 ms 22228 KB Output is correct
15 Correct 13 ms 22108 KB Output is correct
16 Correct 7 ms 12372 KB Output is correct
17 Correct 8 ms 12572 KB Output is correct
18 Correct 8 ms 12500 KB Output is correct
19 Correct 7 ms 12612 KB Output is correct
20 Correct 7 ms 12500 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 22228 KB Output is correct
2 Correct 17 ms 22152 KB Output is correct
3 Correct 15 ms 22144 KB Output is correct
4 Correct 17 ms 22120 KB Output is correct
5 Correct 14 ms 22228 KB Output is correct
6 Correct 13 ms 22228 KB Output is correct
7 Correct 13 ms 22228 KB Output is correct
8 Correct 13 ms 22112 KB Output is correct
9 Correct 14 ms 22228 KB Output is correct
10 Correct 17 ms 22228 KB Output is correct
11 Correct 13 ms 22228 KB Output is correct
12 Correct 13 ms 22172 KB Output is correct
13 Correct 13 ms 22228 KB Output is correct
14 Correct 13 ms 22228 KB Output is correct
15 Correct 13 ms 22108 KB Output is correct
16 Correct 7 ms 12372 KB Output is correct
17 Correct 8 ms 12572 KB Output is correct
18 Correct 8 ms 12500 KB Output is correct
19 Correct 7 ms 12612 KB Output is correct
20 Correct 7 ms 12500 KB Output is correct
21 Incorrect 845 ms 29512 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 14 ms 10928 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 22228 KB Output is correct
2 Correct 17 ms 22152 KB Output is correct
3 Correct 15 ms 22144 KB Output is correct
4 Correct 17 ms 22120 KB Output is correct
5 Correct 14 ms 22228 KB Output is correct
6 Correct 13 ms 22228 KB Output is correct
7 Correct 13 ms 22228 KB Output is correct
8 Correct 13 ms 22112 KB Output is correct
9 Correct 14 ms 22228 KB Output is correct
10 Correct 17 ms 22228 KB Output is correct
11 Correct 13 ms 22228 KB Output is correct
12 Correct 13 ms 22172 KB Output is correct
13 Correct 13 ms 22228 KB Output is correct
14 Correct 13 ms 22228 KB Output is correct
15 Correct 13 ms 22108 KB Output is correct
16 Correct 7 ms 12372 KB Output is correct
17 Correct 8 ms 12572 KB Output is correct
18 Correct 8 ms 12500 KB Output is correct
19 Correct 7 ms 12612 KB Output is correct
20 Correct 7 ms 12500 KB Output is correct
21 Incorrect 845 ms 29512 KB Output isn't correct
22 Halted 0 ms 0 KB -