oj.uz

Submission #209892

# Submission time Handle Problem Language Result Execution time Memory
209892 2020-03-15T21:43:31 Z AQT Boat (APIO16_boat) C++14
27 / 100
 668 ms 6264 KB 
#include <bits/stdc++.h>

using namespace std;

int N;
const long long MOD = 1e9+7;
long long cst[505][505];
long long dp[505][505];
long long choose[505][505];
long long temp[505];
int lft[505], rht[505];
vector<int> cmp;

long long add(long long a, long long b){
	return (a+b)%MOD;
}

long long mult(long long a, long long b){
	return (a*b)%MOD;
}

long long qikpow(long long b, long long e){
	if(!e){
		return 1;
	}
	long long ret = qikpow(b, e>>1);
	ret = mult(ret, ret);
	if(e&1){
		ret = mult(ret, b);
	}
	return ret;
}

long long divd(long long a, long long b){
	return mult(a, qikpow(b, MOD-2));
}

int main(){
	cin.sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> N;
	//cmp.push_back(0);
	for(int i= 1; i<=N; i++){
		cin >> lft[i] >> rht[i];
		cmp.push_back(lft[i]);
		cmp.push_back(rht[i]+1);
	}
	sort(cmp.begin(), cmp.end());
	cmp.erase(unique(cmp.begin(), cmp.end()), cmp.end());
	const int K = cmp.size()-1;
	for(int i = 1; i<=N; i++){
		lft[i] = lower_bound(cmp.begin(), cmp.end(), lft[i]) - cmp.begin();
		rht[i] = lower_bound(cmp.begin(), cmp.end(), rht[i]+1) - cmp.begin();
	}
	choose[0][0] = 1;
	for(int i = 0; i<=N; i++){
		choose[i][0] = 1;
		for(int k = 1; k<=N; k++){
			choose[i][k] = add(choose[i-1][k], choose[i-1][k-1]);
		}
	}
	temp[0] = 1;
	for(int k = 1; k<=K; k++){
		for(int n = 1; n<=N; n++){
			if(n > cmp[k]-cmp[k-1]){
				temp[n] = 0;
			}
			else{
				temp[n] = mult(temp[n-1], cmp[k]-cmp[k-1]-n+1);
				temp[n] = divd(temp[n], n);
			}
		}
		for(int n = 1; n<=N; n++){
			for(int a = 1; a<=n; a++){
				//cout << temp[a] << " " << choose[n-1][a-1] << "\n";
				cst[n][k] = add(cst[n][k], mult(choose[n-1][a-1], temp[a]));
			}
			//cout << n << " " << k << " " << cst[n][k] << "\n";
		}
	}
	for(int k = 0; k<=K; k++){
		dp[0][k] = 1;
	}
	for(int i = 1; i<=N; i++){
		for(int k = 1; k<=K; k++){
			dp[i][k] = dp[i][k-1];
			if(rht[i] >= k && lft[i] < k){
				int cnt = 0;
				for(int j = i; j; j--){
					if(rht[j] >= k && lft[j] < k){
						cnt++;
					}
					dp[i][k] = add(dp[i][k], mult(dp[j-1][k-1], cst[cnt][k]));
				}
			}
		}
	}
	long long ans = 0;
	for(int i = 1; i<=N; i++){
		//cout << dp[i][K] << " ";
		ans = add(ans, dp[i][K]);
	}
	cout << ans << "\n";
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 668 ms 6264 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 668 ms 6264 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 1528 KB Output is correct
2 Correct 18 ms 1528 KB Output is correct
3 Correct 17 ms 1528 KB Output is correct
4 Correct 19 ms 1528 KB Output is correct
5 Correct 18 ms 1528 KB Output is correct
6 Correct 19 ms 1528 KB Output is correct
7 Correct 20 ms 1528 KB Output is correct
8 Correct 19 ms 1528 KB Output is correct
9 Correct 18 ms 1528 KB Output is correct
10 Correct 19 ms 1528 KB Output is correct
11 Correct 17 ms 1528 KB Output is correct
12 Correct 17 ms 1528 KB Output is correct
13 Correct 17 ms 1528 KB Output is correct
14 Correct 17 ms 1528 KB Output is correct
15 Correct 17 ms 1528 KB Output is correct
16 Correct 12 ms 1528 KB Output is correct
17 Correct 11 ms 1528 KB Output is correct
18 Correct 12 ms 1528 KB Output is correct
19 Correct 12 ms 1528 KB Output is correct
20 Correct 12 ms 1528 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Incorrect 668 ms 6264 KB Output isn't correct
2 Halted 0 ms 0 KB -