Submission #40989453

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define op(x) ((x&1)?x+1:x-1)
#define odd(x) (x&1)
#define even(x) (!odd(x))
#define lc(x) (x<<1)
#define rc(x) (lc(x)|1)
#define lowbit(x) (x&-x)
#define mp(x,y) make_pair(x,y)
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
using namespace std;
const int MAXN=1e6+10,LIM=1e6,mod=998244353;
void add(ll& x,ll y){x=(x+y)%mod;}
void sub(ll& x,ll y){x=(x-y+mod)%mod;}
ll addv(ll x,ll y){return (x+y)%mod;}
ll subv(ll x,ll y){return (x-y+mod)%mod;}
ll mypow(ll a,ll n){
    if(!n)return 1;
    ll tmp=mypow(a,n/2);tmp=tmp*tmp%mod;
    if(n&1)tmp=tmp*a%mod;return tmp;
}
ll myinv(ll a){
    return mypow(a,mod-2);
}
ll n,m,ans,res;
ll fact[MAXN],rfact[MAXN];
ll C(ll n,ll m){
    if(m<0 || n<m)return 0;
    return fact[n]*rfact[m]%mod*rfact[n-m]%mod;
}

int main(){
    fact[0]=1;rep(i,1,LIM)fact[i]=fact[i-1]*i%mod;
    rfact[LIM]=myinv(fact[LIM]);per(i,LIM-1,0)rfact[i]=rfact[i+1]*(i+1)%mod;

    cin>>n>>m;
    if(n>m)swap(n,m);
    ans=m;

    rep(i,0,n-1){
        add(res,C(2*i+m-n,i)*C(2*(n-i)-1,n-i)%mod);
    }

    res=res*myinv(C(n+m,n))%mod;

    add(ans,res);

    cout<<ans<<endl;

    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘ll mypow(ll, ll)’:
./Main.cpp:23:5: warning: this ‘if’ clause does not guard... [-Wmisleading-indentation]
   23 |     if(n&1)tmp=tmp*a%mod;return tmp;
      |     ^~
./Main.cpp:23:26: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
   23 |     if(n&1)tmp=tmp*a%mod;return tmp;
      |                          ^~~~~~

Judge Result