oj.uz

답안 #21284

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
21284 2017-04-12T10:03:18 Z suzy 능력 (kriii4_S) C++11
10 / 100
 2000 ms 392052 KB 
#include <stdio.h>
#include <string.h>

typedef long long lli;

#define MOD 1000000007LL

lli p[5001], q[5001], d[5001], fac[5001];
int n;
lli r[5001][5001], rd[5001][5001];

lli ri(int k, int i) {
    if(k==0) return 1;
    if(rd[k][i]>=0) return rd[k][i];
    return rd[k][i]=(r[k][n]-ri(k-1,i)*q[i]%MOD+MOD)%MOD;
}

lli pw(lli n, lli x) {
    if(x==0) return 1;
    if(x%2) return n*pw(n,x-1)%MOD;
    else { lli ret=pw(n,x/2); return ret*ret%MOD; }
}

int main() {
    memset(rd,-1,sizeof(rd));
    fac[0]=1;
    for(lli i=1;i<=5000;i++)
        fac[i]=fac[i-1]*i%MOD;
    scanf("%d",&n);
    for(int i=1;i<=n;i++) {
        scanf("%lld %lld",&p[i],&d[i]);
        q[i]=(1000000000-p[i])*pw(1000000000,MOD-2)%MOD;
        p[i]=p[i]*pw(1000000000,MOD-2)%MOD;
    }
    for(int i=0;i<=5000;i++) {
        r[0][i]=1;
    }
    for(int j=1;j<=n;j++) {
        for(int i=1;i<=n;i++)
            r[i][j]=(r[i-1][j-1]*q[j]%MOD+r[i][j-1])%MOD;
    }
    lli res=0;
    for(int i=1;i<=n;i++) {
        lli mult=p[i]*d[i]%MOD, add=0;
        for(int j=0;j<=n-1;j++) {
            lli ff=fac[j]*fac[n-j-1]%MOD;
            add+=ff*ri(j,i)%MOD;
            add%=MOD;
        }
        res+=add*mult%MOD; res%=MOD;
    }
    res*=pw(fac[n],MOD-2); res%=MOD;
    printf("%lld\n",res);
    return 0;
}

Compilation message

S.cpp: In function 'int main()':
S.cpp:29:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
                   ^
S.cpp:31:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld %lld",&p[i],&d[i]);
                                       ^

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 392052 KB Output is correct
2 Correct 13 ms 392052 KB Output is correct
3 Correct 13 ms 392052 KB Output is correct
4 Correct 9 ms 392052 KB Output is correct
5 Correct 13 ms 392052 KB Output is correct
6 Correct 13 ms 392052 KB Output is correct
7 Correct 9 ms 392052 KB Output is correct
8 Correct 29 ms 392052 KB Output is correct
9 Correct 13 ms 392052 KB Output is correct
10 Correct 33 ms 392052 KB Output is correct
11 Correct 13 ms 392052 KB Output is correct
12 Correct 26 ms 392052 KB Output is correct
13 Correct 16 ms 392052 KB Output is correct
14 Correct 9 ms 392052 KB Output is correct
15 Correct 13 ms 392052 KB Output is correct
16 Correct 26 ms 392052 KB Output is correct
17 Correct 26 ms 392052 KB Output is correct
18 Correct 16 ms 392052 KB Output is correct
19 Correct 26 ms 392052 KB Output is correct
20 Correct 6 ms 392052 KB Output is correct

Subtask #2
0 / 90.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1953 ms 392052 KB Output is correct
2 Correct 1976 ms 392052 KB Output is correct
3 Correct 1999 ms 392052 KB Output is correct
4 Correct 1946 ms 392052 KB Output is correct
5 Execution timed out 2000 ms 392052 KB Execution timed out
6 Halted 0 ms 0 KB -