답안 #20045

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
20045	2016-02-25T08:51:35 Z	suzy	괄호 (kriii4_R)	C++	8 / 100	405 ms	16708 KB

R

#include <stdio.h>
 
#define MOD 1000000007
 
typedef long long lli;
 
lli f[1000001];
lli inv[1000001];
 
lli p(lli a, lli x) {
    if(x==0) return 1;
    if(x%2) return a*p(a,x-1)%MOD;
    else { lli m=p(a,x/2); return m*m%MOD; }
}
 
lli C(lli k) {
    lli ret=f[2*k]*inv[k]%MOD;
    return ret*inv[k+1]%MOD;
}
 
int main() {
    int n, k;
    f[0]=f[1]=1;
    for(lli i=2;i<=1000000;i++)
        f[i]=f[i-1]*i%MOD;
    for(lli i=0;i<=1000000;i++)
        inv[i]=p(f[i],MOD-2);
    scanf("%d %d",&n,&k);
    lli res=0, t=1;
    for(lli l=1;l<=n;l++) {
        if(l%2) t=(t*2-C((l-1)/2)+MOD)%MOD;
        else t=t*2%MOD;
    }
    printf("%lld",t);
}

Subtask #1

8.0 / 8.0

#	결과	실행 시간	메모리	Grader output
1	Correct	399 ms	16708 KB	Output is correct
2	Correct	394 ms	16708 KB	Output is correct
3	Correct	404 ms	16708 KB	Output is correct
4	Correct	402 ms	16708 KB	Output is correct
5	Correct	405 ms	16708 KB	Output is correct
6	Correct	402 ms	16708 KB	Output is correct
7	Correct	394 ms	16708 KB	Output is correct
8	Correct	400 ms	16708 KB	Output is correct
9	Correct	395 ms	16708 KB	Output is correct
10	Correct	398 ms	16708 KB	Output is correct
11	Correct	394 ms	16708 KB	Output is correct
12	Correct	402 ms	16708 KB	Output is correct
13	Correct	396 ms	16708 KB	Output is correct
14	Correct	396 ms	16708 KB	Output is correct
15	Correct	396 ms	16708 KB	Output is correct
16	Correct	396 ms	16708 KB	Output is correct
17	Correct	404 ms	16708 KB	Output is correct
18	Correct	403 ms	16708 KB	Output is correct
19	Correct	398 ms	16708 KB	Output is correct
20	Correct	403 ms	16708 KB	Output is correct

Subtask #2

0.0 / 92.0

#	결과	실행 시간	메모리	Grader output
1	Incorrect	399 ms	16708 KB	Output isn't correct
2	Halted	0 ms	0 KB	-