#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod = 998244353;
int x[205],y[205];
ll s[210];
int main(){
int n;
memset(s,0,sizeof(s));
s[0]=1;
scanf("%d", &n);
for(int i = 0; i < n; i++){
scanf("%d%d", &x[i], &y[i]);
s[i + 1] = (s[i] * 2) % mod;
}
ll sum = (s[n] - n - 1 + mod) % mod;//去掉空集和只有一个的点
for(int i = 0; i < n; i++){
for(int j = i + 1; j < n; j++){
int temp = 0;
for(int k = j + 1; k < n; k++){
if((x[i] - x[j]) * (y[i] - y[k]) == (x[i] - x[k]) * (y[i] - y[j])){
temp++;
}
}
sum = (sum - s[temp] + mod) % mod;//去掉共线的点
}
}
printf("%lld", sum);
return 0;
}
UPC
最新推荐文章于 2022-05-13 01:20:00 发布