Submission #1044022

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044022		guagua0407	Portal (BOI24_portal)	C++17	1 / 100	16 ms	1612 KiB

Main

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

int main() {_
    int n;
    cin>>n;
    if(n<=2){
        cout<<-1<<'\n';
        return 0;
    }
    pair<ll,ll> st,a,b;
    cin>>st.f>>st.s>>a.f>>a.s;
    a.f-=st.f;
    a.s-=st.s;
    if(a.f<0){
        a.f*=-1;
        a.s*=-1;
    }
    vector<ll> ys;
    auto go=[&](){
        if(a.f<b.f) swap(a,b);
        while(b.f!=0){
            ll c=a.f/b.f;
            a.f-=c*b.f;
            a.s-=c*b.s;
            if(a.f<b.f) swap(a,b);
        }
        ys.push_back(abs(b.s));
    };
    for(int i=0;i<n-2;i++){
        cin>>b.f>>b.s;
        b.f-=st.f;
        b.s-=st.s;
        if(b.f<0){
            b.f*=-1;
            b.s*=-1;
        }
        go();
    }
    ll g=ys[0];
    for(int i=1;i<(int)ys.size();i++){
        g=__gcd(g,ys[i]);
    }
    g=__gcd(g,abs(a.s));
    ll ans=abs(g*a.f);
    cout<<(ans==0?-1:ans)<<'\n';
    return 0;
}
//maybe its multiset not set
//yeeorz
//laborz

Compilation message (stderr)

Main.cpp: In function 'void setIO(std::string)':
Main.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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