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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#314774 | #8171. Cola | ucup-team1447# | RE | 317ms | 245360kb | C++14 | 2.5kb | 2024-01-26 10:50:03 | 2024-01-26 10:50:04 |
Judging History
answer
// what is matter? never mind.
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
//#define int long long
using namespace std;
inline int read()
{
char c=getchar();int x=0;bool f=0;
for(;!isdigit(c);c=getchar())f^=!(c^45);
for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
if(f)x=-x;return x;
}
#define mod 998244353
struct modint{
int x;
modint(int o=0){x=o;}
modint &operator = (int o){return x=o,*this;}
modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
modint &operator ^=(int b){
modint a=*this,c=1;
for(;b;b>>=1,a*=a)if(b&1)c*=a;
return x=c.x,*this;
}
modint &operator /=(modint o){return *this *=o^=mod-2;}
friend modint operator +(modint a,modint b){return a+=b;}
friend modint operator -(modint a,modint b){return a-=b;}
friend modint operator *(modint a,modint b){return a*=b;}
friend modint operator /(modint a,modint b){return a/=b;}
friend modint operator ^(modint a,int b){return a^=b;}
friend bool operator ==(modint a,modint b){return a.x==b.x;}
friend bool operator !=(modint a,modint b){return a.x!=b.x;}
bool operator ! () {return !x;}
modint operator - () {return x?mod-x:0;}
bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}
vector<modint> fac,ifac,iv;
inline void initC(int n)
{
if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
int m=iv.size(); ++n;
if(m>=n)return;
iv.resize(n),fac.resize(n),ifac.resize(n);
For(i,m,n-1){
iv[i]=iv[mod%i]*(mod-mod/i);
fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
}
}
inline modint C(int n,int m){
if(m<0||n<m)return 0;
return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}
#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;
#define maxn 2000005
#define inf 0x3f3f3f3f
int n,m;
modint f[maxn];
modint F(int up,int n){
return C(n+up-1,up-1);
}
signed main()
{
n=read(),m=read()-1;
for(int k=0; ;++k){
int t1=k*(3*k-1)/2;
int t2=k*(3*k+1)/2;
modint o=sign(k);
if(t1<=m) f[t1]+=o;
if(t2<=m && k!=0) f[t2]+=o;
if(t1>m&&t2>m)break;
}
//For(i,0,m)cout<<f[i].x<<" ";cout<<"\n";
initC(20000000);
modint res=0;
For(i,0,m) if(f[i].x) res+=f[i]*F(n+1,m-i);
res*=ifac[n];
cout<<res.x;
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 317ms
memory: 245156kb
input:
2 1
output:
499122177
result:
ok "499122177"
Test #2:
score: 0
Accepted
time: 263ms
memory: 245256kb
input:
1 1
output:
1
result:
ok "1"
Test #3:
score: 0
Accepted
time: 273ms
memory: 245360kb
input:
167 91
output:
469117530
result:
ok "469117530"
Test #4:
score: -100
Runtime Error
input:
9806463 8975779