답안 #19008

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
19008 2016-02-17T02:57:20 Z kriii 능력 (kriii4_S) C++14
100 / 100
175 ms 1280 KB
#include <stdio.h>
#include <algorithm>
using namespace std;

const long long mod = 1000000007;

long long fpow(long long a, long long p)
{
	a %= mod;
	p = (p % (mod - 1) + mod - 1) % (mod - 1);
	long long r = 1;
	while (p){
		if (p & 1) r = r * a % mod;
		a = a * a % mod;
		p /= 2;
	}
	return r;
}

long long inv[5005],p[5005],d[5005],bit[2][5005];

int main()
{
	int n; scanf ("%d",&n);

	inv[1] = 1;
	for (int i=2;i<=n;i++) inv[i] = (mod - mod / i) * inv[mod % i] % mod;

	long long pc=fpow(1000000000,-1);
	for (int i=0;i<n;i++){
		scanf ("%lld %lld",&p[i],&d[i]);
		p[i] = p[i] * pc % mod;
	}

	long long sum = 0;
	for (int i=0;i<=n;i++) bit[0][i] = bit[1][i] = 0;
	bit[0][0] = 1;
	for (int i=0;i<n;i++){
		for (int j=i;j>=0;j--){
			bit[1][j+1] = (bit[1][j+1] + bit[0][j] * p[i] % mod * d[i]) % mod;
			bit[1][j+1] = (bit[1][j+1] + bit[1][j] * p[i]) % mod;
			bit[0][j+1] = (bit[0][j+1] + bit[0][j] * p[i]) % mod;
		}
	}
	for (int i=1;i<=n;i++){
		long long add = bit[1][i] * inv[i] % mod;
		if (i & 1) sum = (sum + add) % mod;
		else sum = (sum + mod - add) % mod;
	}
	printf ("%lld\n",sum);

	return 0;
}
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 1280 KB Output is correct
2 Correct 0 ms 1280 KB Output is correct
3 Correct 0 ms 1280 KB Output is correct
4 Correct 0 ms 1280 KB Output is correct
5 Correct 0 ms 1280 KB Output is correct
6 Correct 0 ms 1280 KB Output is correct
7 Correct 1 ms 1280 KB Output is correct
8 Correct 0 ms 1280 KB Output is correct
9 Correct 0 ms 1280 KB Output is correct
10 Correct 0 ms 1280 KB Output is correct
11 Correct 0 ms 1280 KB Output is correct
12 Correct 0 ms 1280 KB Output is correct
13 Correct 0 ms 1280 KB Output is correct
14 Correct 0 ms 1280 KB Output is correct
15 Correct 0 ms 1280 KB Output is correct
16 Correct 0 ms 1280 KB Output is correct
17 Correct 0 ms 1280 KB Output is correct
18 Correct 0 ms 1280 KB Output is correct
19 Correct 0 ms 1280 KB Output is correct
20 Correct 0 ms 1280 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 175 ms 1280 KB Output is correct
2 Correct 171 ms 1280 KB Output is correct
3 Correct 175 ms 1280 KB Output is correct
4 Correct 175 ms 1280 KB Output is correct
5 Correct 175 ms 1280 KB Output is correct
6 Correct 174 ms 1280 KB Output is correct
7 Correct 174 ms 1280 KB Output is correct
8 Correct 175 ms 1280 KB Output is correct
9 Correct 174 ms 1280 KB Output is correct
10 Correct 175 ms 1280 KB Output is correct
11 Correct 175 ms 1280 KB Output is correct
12 Correct 173 ms 1280 KB Output is correct
13 Correct 173 ms 1280 KB Output is correct
14 Correct 174 ms 1280 KB Output is correct
15 Correct 171 ms 1280 KB Output is correct
16 Correct 174 ms 1280 KB Output is correct
17 Correct 174 ms 1280 KB Output is correct
18 Correct 174 ms 1280 KB Output is correct
19 Correct 172 ms 1280 KB Output is correct
20 Correct 174 ms 1280 KB Output is correct