Submission #1054672

#	Time	Username	Problem	Language	Result	Execution time	Memory
1054672		anango	Portal (BOI24_portal)	C++17	50 / 100	62 ms	2592 KiB

Main

#include <bits/stdc++.h>
#define int long long
using namespace std;

mt19937 rng;

vector<pair<int,int>> cords;

int area(int i, int j, int k) {
    return cords[i].first*cords[j].second-cords[i].second*cords[j].first+cords[j].first*cords[k].second-cords[j].second*cords[k].first+cords[k].first*cords[i].second-cords[k].second*cords[i].first;
}

signed main() {
    int local = 0;
    if (local) {
        // for getting input from input.txt
        freopen("input.txt", "r", stdin);
        // for writing output to output.txt
        freopen("output.txt", "w", stdout);
    }
    #ifdef ONLINE_JUDGE
    	ios_base::sync_with_stdio(false);
    	cin.tie(NULL);
    #endif //fast IO
    int n; cin >> n;
    for (int i=0; i<n; i++) {
        int x,y; cin >> x >> y; 
        cords.push_back({x,y});
    }
    sort(cords.begin(), cords.end());
    int g = 0;
    for (int it=0; it<500000; it++) {
        int j,k;
        j=rng()%n; k=rng()%n;
        //cout << i <<" " << j <<" " << k <<" " << area(i,j,k) << endl;
        g=gcd(g,area(0,j,k));
    }
    g=abs(g);
    if (g==0) {
        cout << -1 << endl;
    }
    else {
        cout << g << endl;
    }
    
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:17:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         freopen("input.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:19:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen("output.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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