Submission #994640

#	Time	Username	Problem	Language	Result	Execution time	Memory
994640		PenguinsAreCute	Portal (BOI24_portal)	C++17	55 / 100	2089 ms	1116 KiB

Main

// yay linear algebra!
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
main() {
	int n; cin >> n;
	int x[n], y[n]; for(int i=0;i<n;i++) cin>>x[i]>>y[i];
	for(int i=1;i<n;i++) x[i]-=x[0],y[i]-=y[0];
	int g = 0; for(int i=1;i<n;i++) g=__gcd(g,x[i]);
	g=abs(g);
	if(!g) {cout<<"-1"; return 0;}
	for(int i=1;i<n;i++) x[i]/=g;
	ll g2 = 0;
	for(int i=1;i<n;i++) for(int j=i+1;j<n;j++) g2=__gcd(g2,1LL*x[i]*y[j]-1LL*x[j]*y[i]);
	if(!g2) {cout<<"-1"; return 0;}
	cout << abs(g * g2) << "\n";
}

Compilation message (stderr)

Main.cpp:5:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    5 | main() {
      | ^~~~

• Subtask 1: 1 / 1
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 29 / 29
• Subtask 5: 15 / 15
• Subtask 6: 0 / 35