Submission #1748582

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=210,mod=998244353;
int inc(int x,int y){x+=y;return x>=mod?x-mod:x;}
int dec(int x,int y){x-=y;return x<0?x+mod:x;}
int mul(int x,int y){return (ll)x*y%mod;}
int power(int x,int y){
	int ans=1;
	for (;y;y>>=1,x=mul(x,x))
		if (y&1) ans=mul(ans,x);
	return ans;
}
int calc(int n){
	return dec(power(2,n),n*(n+1)/2+1);
}
typedef pair<int,int> pii;
pii operator - (pii a,pii b){
	return pii(a.first-b.first,a.second-b.second);
}
int operator * (pii a,pii b){
	return a.first*b.second-a.second*b.first;
}
int n,q[N],size;pii p[N];
bool use[N][N];
int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;i++) scanf("%d%d",&p[i].first,&p[i].second);
	int ans=calc(n);
	for (int i=1;i<=n;i++)
	for (int j=1;j<i;j++)
	if (!use[i][j]){
		pii vec=p[i]-p[j];size=0;
		for (int k=1;k<=n;k++)
			if ((p[k]-p[j])*vec==0) q[++size]=k;
		ans=dec(ans,calc(size));
		for (int a=1;a<=size;a++)
		for (int b=1;b<=size;b++)
			use[q[a]][q[b]]=1;
	}
	printf("%d\n",ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:28:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:29:63: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for (int i=1;i<=n;i++) scanf("%d%d",&p[i].first,&p[i].second);
                                                               ^

Judge Result