Submission #1647548

---

Source Code Expand

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>

#define For(i, j, k) for(int i = j; i <= k; i++)
#define Forr(i, j, k) for(int i = j; i >= k; i--)

using namespace std;

const int Mod = 998244353;

const int N = 310;

struct Point{
	int x, y;
}P[N];

int n, Pow[N];
double s[N];

int main(){
	scanf("%d", &n);
	Pow[0] = 1;
	For(i, 1, n) scanf("%d%d", &P[i].x, &P[i].y), Pow[i] = Pow[i - 1] * 2 % Mod;
	int ans = Pow[n] - n;
	For(i, 1, n){
		int c = 0;
		For(j, i + 1, n) s[++c] = P[i].x == P[j].x ? 1e10 : double(P[j].y - P[i].y) / double(P[j].x - P[i].x);
		sort(s + 1, s + c + 1);
		For(j, 1, c){
			int r = j;
			while(r < c && fabs(s[r + 1] - s[j]) < 1e-10) ++r;
			ans = (Mod + ans - Pow[r - j + 1] + 1) % Mod;
			j = r;
		}
	}
	printf("%d\n", (ans + Mod - 1) % Mod);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:24:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
./Main.cpp:26:77: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  For(i, 1, n) scanf("%d%d", &P[i].x, &P[i].y), Pow[i] = Pow[i - 1] * 2 % Mod;
                                                                             ^

Judge Result