답안 #633656

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
633656	2022-08-23T01:07:56 Z	lkh3happy	팔찌 (kriii4_V)	C++14	100 / 100	465 ms	23736 KB

V

#include <stdio.h>
#include <algorithm>
#include <vector>
using namespace std;

long long mod=1e9+7, ep[1000001], mi[1000001]={1}, kp[1000001]={1};

long long po(long long x){
    long long sum=1, y=mod-2;
    for(;y;y>>=1, x=x*x%mod) if(y&1) sum=sum*x%mod;
    return sum;
}

int main(){
    long long n, k, ans=0;
    scanf("%lld%lld\n", &n, &k);
    for(int i=1;i<=n;i++) ep[i]=i;
    for(int i=2;i<=n;i++) if(ep[i]==i) for(int j=i;j<=n;j+=i) ep[j]=ep[j]/i*(i-1);
    for(int i=1;i<=max(n, 4LL);i++) kp[i]=kp[i-1]*k%mod, ep[i]=(ep[i]*(mi[i]=po(i))+ep[i-1])%mod;
    for(int i=1;i<=n;i++) ans=(ans+(kp[i]*mi[i]%mod)*ep[n/i]*2+((i&1)?kp[i/2+1]*2:kp[i/2]+kp[i/2+1]))%mod;
    printf("%lld\n", (ans*mi[4]+1)%mod);
    return 0;
}

Compilation message

V.cpp: In function 'int main()':
V.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     scanf("%lld%lld\n", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1

6.0 / 6.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	0 ms	212 KB	Output is correct
3	Correct	0 ms	212 KB	Output is correct
4	Correct	0 ms	212 KB	Output is correct
5	Correct	0 ms	212 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	0 ms	212 KB	Output is correct
8	Correct	0 ms	212 KB	Output is correct
9	Correct	0 ms	212 KB	Output is correct
10	Correct	0 ms	212 KB	Output is correct
11	Correct	0 ms	300 KB	Output is correct
12	Correct	0 ms	212 KB	Output is correct
13	Correct	0 ms	212 KB	Output is correct
14	Correct	1 ms	212 KB	Output is correct
15	Correct	0 ms	296 KB	Output is correct
16	Correct	0 ms	212 KB	Output is correct
17	Correct	0 ms	212 KB	Output is correct
18	Correct	0 ms	212 KB	Output is correct
19	Correct	0 ms	212 KB	Output is correct
20	Correct	0 ms	212 KB	Output is correct

Subtask #2

94.0 / 94.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	27 ms	1464 KB	Output is correct
5	Correct	289 ms	14808 KB	Output is correct
6	Correct	347 ms	17904 KB	Output is correct
7	Correct	282 ms	14108 KB	Output is correct
8	Correct	336 ms	17240 KB	Output is correct
9	Correct	377 ms	19548 KB	Output is correct
10	Correct	449 ms	22720 KB	Output is correct
11	Correct	384 ms	19624 KB	Output is correct
12	Correct	448 ms	22032 KB	Output is correct
13	Correct	257 ms	13368 KB	Output is correct
14	Correct	415 ms	21216 KB	Output is correct
15	Correct	241 ms	12644 KB	Output is correct
16	Correct	297 ms	15040 KB	Output is correct
17	Correct	459 ms	23552 KB	Output is correct
18	Correct	281 ms	14184 KB	Output is correct
19	Correct	347 ms	17212 KB	Output is correct
20	Correct	465 ms	23736 KB	Output is correct