Submission #1777116

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Source Code Expand

#include<bits/stdc++.h>
#define fi first
#define se second

using namespace std;
typedef long long ll;
typedef pair<ll,ll> pi;
typedef pair<pi,pi> ppi;

const int N=205,P=998244353;

map<ppi,int>D;
int n,x[N],y[N],p2[N],m,t;

inline int gcd(int x,int y){return y?gcd(y,x%y):x;}
inline pi mk(pi x){
	ll g=gcd(x.fi,x.se);
	if(g)x.fi/=g,x.se/=g;
	if(x.fi<0)x.fi=-x.fi,x.se=-x.se;
	else if(x.fi==0&&x.se<0)x.se=-x.se;
	return x;
}
inline ppi mp(ll u1,ll v1,ll u2,ll v2){
	pi l=mk({u2-u1,v2-v1}),s;
	if(l.fi)s=mk({v1*l.fi-u1*l.se,l.fi});else s={u1,0};
	return {l,s};
}
inline int get(int s){return (1+sqrt(1+8*s+0.5))/2;}

int main(){
	scanf("%d",&n);
	p2[0]=1;
	for(int i=1;i<=n;i++)p2[i]=(p2[i-1]<<1)%P,scanf("%d%d",&x[i],&y[i]);
	for(int i=1;i<=n;i++)for(int j=1;j<i;j++)D[mp(x[i],y[i],x[j],y[j])]++;
	m=p2[n];
	for(auto&i:D)t=get(i.se),m=(m-p2[t]+t+1+P)%P;
	m=(m-n-1+P)%P;
	printf("%d\n",m);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:31:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:33:69: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;i++)p2[i]=(p2[i-1]<<1)%P,scanf("%d%d",&x[i],&y[i]);
                                                                     ^

Judge Result