Submission #1165881

#	Time	Username	Problem	Language	Result	Execution time	Memory
1165881		Math4Life2020	Portal (BOI24_portal)	C++20	11 / 100	25 ms	2496 KiB

Main

#include <bits/stdc++.h>
using namespace std;
using ll = long long; using pii = pair<ll,ll>;

ll gcd2(ll a, ll b) {
    a = labs(a); b = labs(b);
    if (a==0) {
        return b;
    }
    if (b==0) {
        return a;
    }
    return gcd(a,b);
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
	ll N; cin >> N;
    ll ans = 0;
    if (N<=2) {
        cout << "-1\n"; exit(0);
    }
    vector<pii> v0;
    pii p0;
    ll x1,y1; cin >> x1 >> y1;
    p0 = {x1,y1};
    for (ll i=1;i<N;i++) {
        ll x2,y2; cin >> x2 >> y2;
        v0.push_back({x2-x1,y2-y1});
    }
    for (ll i=1;i<(N-1);i++) {
        ans = gcd2(ans,v0[i].first*v0[0].second-v0[i].second*v0[0].first);
    }
    if (ans==0) {
        cout << "-1\n";
    } else {
        cout << ans << "\n";
    }

}

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