Submission #1675027

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Source Code Expand

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

const int MAX_N = 205, MOD = 998244353;

class Point {
public:
  int x, y;
  Point(int _x = 0, int _y = 0) {
    x = _x, y = _y;
  }
  inline friend Point operator + (const Point &a, const Point &b) {
    return Point(a.x + b.x, a.y + b.y);
  }
  inline friend Point operator - (const Point &a, const Point &b) {
    return Point(a.x - b.x, a.y - b.y);
  }
} P[MAX_N];

int pw[MAX_N];

int cross(Point a, Point b) {
  return a.x * b.y - a.y * b.x;
}

int vis[MAX_N][MAX_N], st[MAX_N];

int main() {
  int N;
  scanf("%d", &N);
  for (int i = 1; i <= N; ++i) scanf("%d%d", &P[i].x, &P[i].y);
  pw[0] = 1;
  for (int i = 1; i <= N; ++i) pw[i] = (pw[i - 1] + pw[i - 1]) % MOD;

  int result = pw[N] - 1;

  for (int i = 1; i <= N; ++i)
    for (int j = i + 1; j <= N; ++j) 
      if (!vis[i][j]) {
	int top = 0;
	for (int k = 1; k <= N; ++k)
	  if (cross(P[k] - P[i], P[k] - P[j]) == 0) st[++top] = k;
	result = (result - pw[top] + 1 + top) % MOD;
	for (int k1 = 1; k1 <= top; ++k1)
	  for (int k2 = 1; k2 <= top; ++k2)
	    vis[st[k1]][st[k2]] = 1;
      }
  result = (result - N) % MOD;
  printf("%d\n", (result + MOD) % MOD);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:32:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &N);
                  ^
./Main.cpp:33:63: 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].x, &P[i].y);
                                                               ^

Judge Result