Submission #2615464

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Source Code Expand

#include <cstdio>
#include <cstdlib>
#include <algorithm>
#define fo(i,a,b) for(LL i=a;i<=b;++i)
#define fod(i,a,b) for(int i=a;i>=b;--i)
#define max(q,w) ((q)>(w)?(q):(w))
using namespace std;
typedef long long LL;
const int N=1000500,mo=998244353;
int m,n;
LL ans,jc[N],jcn[N];
LL ksm(LL q,int w)
{
    LL ans=1;
    for(;w;w>>=1,q=q*q%mo)if(w&1)ans=ans*q%mo;
    return ans;
}
LL C(int m,int n){return jc[m]*jcn[n]%mo*jcn[m-n]%mo;}
int main()
{
    scanf("%d%d",&n,&m);
    jc[0]=1;fo(i,1,n+m)jc[i]=jc[i-1]*(LL)i%mo;
    jcn[n+m]=ksm(jc[n+m],mo-2);fod(i,m+n-1,0)jcn[i]=jcn[i+1]*(i+1LL)%mo;
    if(n<m)swap(n,m);
    fo(i,1,m)ans=(ans+C(i*2,i)*C(n+m-i*2,m-i)%mo)%mo;
    printf("%lld\n",(ans*ksm(2,mo-2)%mo*ksm(C(m+n,m),mo-2)+n)%mo);
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:21:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
                        ^

Judge Result