Submission #998194

#	Time	Username	Problem	Language	Result	Execution time	Memory
998194		yeediot	Portal (BOI24_portal)	C++17	21 / 100	26 ms	3672 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
#ifdef local
void CHECK();
void setio(){
    freopen("/Users/iantsai/cpp/input.txt","r",stdin);
    freopen("/Users/iantsai/cpp/output.txt","w",stdout);
}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
#define TOI_is_so_de ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);setio();
const int mxn = 1e5+5;
int n, dx[mxn], dy[mxn];
vector<pii>vec, p;
void exgcd(int a, int b){
    if(vec[b].F == 0)return;
    if(vec[a].F < 0){
        vec[a].F *= -1;
        vec[a].S *= -1;
    }
    if(vec[b].F < 0){
        vec[b].F *= -1;
        vec[b].S *= -1;
    }
    if(vec[a].F < vec[b].F) swap(a, b);       
    int q=vec[a].F/vec[b].F;
    vec[a].F -= q*vec[b].F;
    exgcd(b, a);
}
void cal(){
    for(int i=0;i<2;i++){
        if(vec[0].F < 0){
            vec[0].F *= -1;
            vec[0].S *= -1;
        }
        if(vec[1].F < 0){
            vec[1].F *= -1;
            vec[1].S *= -1;
        }
        if(vec[0].F < vec[1].F) swap(vec[0], vec[1]);
        exgcd(0, 1);
        if(vec[0].F == 0)swap(vec[0], vec[2]);
        else swap(vec[1], vec[2]);
    }
    debug(vec);
    vector<pii>temp;
    int g = 0;
    for(int i=0;i<3;i++){
        if(vec[i].F) temp.pb(vec[i]);
        else g = gcd(g, vec[i].S);
    }
    temp.pb({0,g});
    vec = temp;
}
signed main(){
    TOI_is_so_de;
    ykh;
    cin >> n;
    p.resize(n);
    for(int i=0;i<n;i++){
        cin >> p[i].F >> p[i].S;
    }
    //random_shuffle(all(p));
    //sort(p+1, p+1+n, [&](pii i, pii j){return rng()&1 ? 1 : 0;});
    for(int i=1;i<n;i++){
        dx[i] = p[i].F-p[i-1].F;
        dy[i] = p[i].S-p[i-1].S;
    }
    for(int i=1;i<n;i++){
        vec.pb({dx[i], dy[i]});
        if(sz(vec)>=3)cal();
    }
    if(sz(vec)<=1){
        cout << -1 << '\n';
    }
    else{
        int x = vec[0].F*vec[1].S-vec[1].F*vec[0].S;
        cout << (x == 0 ? -1 : abs(x));
    }
    #ifdef local
    CHECK();
    #endif
}
/*
input:
 
*/
#ifdef local
void CHECK(){
    cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
     function<bool(string,string)> compareFiles = [](string p1, string p2)->bool {
         std::ifstream file1(p1);
         std::ifstream file2(p2);
         if (!file1.is_open() || !file2.is_open())return false;
         std::string line1, line2;
         while (getline(file1, line1) && getline(file2, line2)) {
             if (line1 != line2)return false;
         }
         int cnta=0,cntb=0;
         while(getline(file1,line1))cnta++;
         while(getline(file2,line2))cntb++;
         return cntb-cnta<=1;
     };
     bool check = compareFiles("output.txt","expected.txt");
     if (check) cerr<<"ACCEPTED\n";
     else cerr<<"WRONG ANSWER!\n";
}
#else
#endif



 

Compilation message (stderr)

Main.cpp: In function 'void setIO(std::string)':
Main.cpp:35:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:36:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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