Submission #2997093

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll ms=998244353;
ll ans=0,inv[1000005],fac[1000005];
ll C(ll n,ll k){
	return fac[n]*inv[k]%ms*inv[n-k]%ms;
}
int main(){
	int n,m;
	scanf("%d%d",&n,&m);
	if (n<m) swap(n,m);
	inv[0]=inv[1]=fac[0]=fac[1]=1;
	for (int i=2;i<=n+m;i++){
		inv[i]=(ll)(ms-ms/i)*inv[ms%i]%ms; fac[i]=fac[i-1]*i%ms;
	}
	for (int i=2;i<=n+m;i++)
	inv[i]=inv[i]*inv[i-1]%ms;
	for (int i=1;i<=m;i++){
		ll p=inv[2]*C(2*i,i)%ms*C(n+m-2*i,n-i)%ms;
	    ans=(ans+p)%ms;
	}
	ans=ans*fac[n]%ms*fac[m]%ms*inv[n+m]%ms;
	ans=(ans+n)%ms;
	printf("%lld\n",ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:11:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^

Judge Result