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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#769888 | #9553. The Hermit | Nana7# | WA | 178ms | 20108kb | C++14 | 1.3kb | 2024-11-21 19:46:35 | 2024-11-21 19:46:36 |
Judging History
answer
#include<iostream>
#include<cstdio>
#include<cstring>
#include<vector>
#define I inline
#define int long long
using namespace std;
const int mod = 998244353;
const int N = 100010;
const int LG = 19;
int mul[N],inv[N],f[LG][N];
int n,m,red,ans;
int qpow(int x,int y) {
if(y==0) return 1;
if(y==1) return x;
int mk=qpow(x,y/2);
return y%2?mk*mk%mod*x%mod:mk*mk%mod;
}
I int C(int x,int y) {
if(x<y) return 0;
return mul[x]*inv[y]%mod*inv[x-y]%mod;
}
I void deal(int x) {
for(int i=1;i*x<=m;++i) {
int nxt=i*x;
for(int pre=0;pre<=18;++pre) {
int nd=n-pre-2,hv1=m/nxt-1,hv2=m/x-(nxt/x);
if(hv2<nd||nd<0) continue;
red+=f[pre][x]*(C(hv2,nd)-C(hv1,nd)+mod)%mod*(pre+1)%mod;
red%=mod;
}
if(n<=18) {
red+=f[n-1][x]*n%mod;
red%=mod;
}
}
//cout<<red<<endl;
}
signed main()
{
{
mul[0]=inv[0]=1;
for(int i=1;i<=100000;++i) mul[i]=mul[i-1]*i%mod;
inv[100000]=qpow(mul[100000],mod-2);
for(int i=99999;i>=1;--i) inv[i]=inv[i+1]*(i+1)%mod;
}
// cout<<C(100000,99999)<<endl;
for(int i=1;i<=100000;++i) {
f[0][i]=1;
for(int j=1;j<=18;++j) {
for(int k=2;k*i<=100000;++k) {
f[j][k*i]+=f[j-1][i];
f[j][k*i]%=mod;
}
}
}
cin>>m>>n;
if(n==1) {
cout<<0<<endl;
return 0;
}
for(int i=1;i<=m;++i) {
deal(i);
}
cout<<(C(m,n)*n%mod-red+mod)%mod<<endl;
}
詳細信息
Test #1:
score: 100
Accepted
time: 58ms
memory: 20048kb
input:
4 3
output:
7
result:
ok 1 number(s): "7"
Test #2:
score: 0
Accepted
time: 66ms
memory: 20064kb
input:
11 4
output:
1187
result:
ok 1 number(s): "1187"
Test #3:
score: 0
Accepted
time: 79ms
memory: 20052kb
input:
100000 99999
output:
17356471
result:
ok 1 number(s): "17356471"
Test #4:
score: 0
Accepted
time: 72ms
memory: 20056kb
input:
11451 1919
output:
845616153
result:
ok 1 number(s): "845616153"
Test #5:
score: 0
Accepted
time: 99ms
memory: 20104kb
input:
99998 12345
output:
936396560
result:
ok 1 number(s): "936396560"
Test #6:
score: 0
Accepted
time: 67ms
memory: 20108kb
input:
100000 1
output:
0
result:
ok 1 number(s): "0"
Test #7:
score: -100
Wrong Answer
time: 178ms
memory: 20104kb
input:
100000 15
output:
190061165
result:
wrong answer 1st numbers differ - expected: '190067060', found: '190061165'