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Submission #532627

# Submission time Handle Problem Language Result Execution time Memory
532627 2022-03-03T11:54:47 Z stefantaga Geometrija (COCI21_geometrija) C++14
50 / 110
 1000 ms 7508 KB 
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
struct Punct
{
    long long x,y;
};
long long determinant (Punct a,Punct b,Punct c)
{
    return a.x*b.y+b.x*c.y+a.y*c.x-a.y*b.x-b.y*c.x-a.x*c.y;
}
bool compare (Punct a, Punct b)
{
    return a.x<b.x||(a.x==b.x&&a.y<b.y);
}
ll n,i,st[4005],q,viz[4005];
Punct v[1005];
struct Triangle
{
    ll a,b,c;
};
ll ok[1005],primul;
vector <Triangle> triunghiuri;
long long ABS(long long x)
{
    if (x>0)
    {
        return x;
    }
    return -x;
}
bool sgn(ll x)
{
    if (x>=0)
    {
        return 1;
    }
    return 0;
}
bool seinter(pair <Punct,Punct> dreapta1,pair <Punct,Punct> dreapta2)
{
    ll det1=determinant(dreapta1.first,dreapta1.second,dreapta2.first);
    ll det2=determinant(dreapta1.first,dreapta1.second,dreapta2.second);
    ll det3=determinant(dreapta2.first,dreapta2.second,dreapta1.first);
    ll det4=determinant(dreapta2.first,dreapta2.second,dreapta1.second);

    if (!det1||!det2||!det3||!det4)
    {
        return 0;
    }
    if (sgn(det1)==sgn(det2))
    {
        return 0;
    }
    if (sgn(det3)==sgn(det4))
    {
        return 0;
    }
    return 1;
}
ll Marc[1005][1005],j;
vector <pair <int,int>> candidati;
int main()
{
    ios_base :: sync_with_stdio(false);
    cin.tie(0);
#ifdef HOME
    ifstream cin("date.in");
    ofstream cout("date.out");
#endif // HOME
    cin>>n;
    for (i=1; i<=n; i++)
    {
        cin>>v[i].x>>v[i].y;
    }
    sort (v+1,v+n+1,compare);
    st[++q]=1;
    st[++q]=2;
    viz[1]=viz[2]=1;
    for (i=3; i<=n; i++)
    {
        while (q>1&&determinant(v[st[q-1]],v[st[q]],v[i])<0)
        {
            viz[st[q]]=0;
            q--;
        }
        viz[i]=1;
        st[++q]=i;
    }
    for (i=n; i>=1; i--)
    {
        if (viz[i]==0)
        {
            while (q>1&&determinant(v[st[q-1]],v[st[q]],v[i])<0)
            {
                viz[st[q]]=0;
                q--;
            }
            viz[i]=1;
            st[++q]=i;
        }
    }
    while (q>1&&determinant(v[st[q-1]],v[st[q]],v[1])<0)
    {
        q--;
    }
    for (i=1; i<=q; i++)
    {
        ok[st[i]]=1;
    }
    for (i=1; i<=n; i++)
    {
        if (ok[i]==0)
        {
            primul= i ;
            break;
        }
    }
    ok[primul]=1;
    for (i=1; i<q; i++)
    {
        triunghiuri.push_back({st[i],st[i+1],primul});
    }
    triunghiuri.push_back({st[1],st[q],primul});
    for (i=1; i<=n; i++)
    {
        if (ok[i]==0)
        {
            ll loc=0;
            for (ll j=0; j<triunghiuri.size(); j++)
            {
                ll x=triunghiuri[j].a,y=triunghiuri[j].b,z=triunghiuri[j].c;
                ll val1 = ABS(determinant(v[x],v[y],v[i]));
                ll val2 = ABS(determinant(v[y],v[z],v[i]));
                ll val3 = ABS(determinant(v[z],v[x],v[i]));
                ll valfin = ABS(determinant(v[x],v[y],v[z]));
                if (val1+val2+val3==valfin)
                {
                    loc = j;
                    break;
                }
            }
            Triangle triunghi1= {triunghiuri[loc].a,triunghiuri[loc].b,i};
            Triangle triunghi2= {triunghiuri[loc].a,triunghiuri[loc].c,i};
            Triangle triunghi3= {triunghiuri[loc].b,triunghiuri[loc].c,i};
            triunghiuri.erase(triunghiuri.begin()+loc);
            triunghiuri.push_back(triunghi1);
            triunghiuri.push_back(triunghi2);
            triunghiuri.push_back(triunghi3);
        }
    }
    for (ll j=0; j<triunghiuri.size(); j++)
    {
        ll x=triunghiuri[j].a,y=triunghiuri[j].b,z=triunghiuri[j].c;
        Marc[x][y]=Marc[y][x]=Marc[x][z]=Marc[z][x]=Marc[z][y]=Marc[y][z]=1;
    }
    for (i=1; i<=n; i++)
    {
        for (j=i+1; j<=n; j++)
        {
            if (Marc[i][j])
            {
                candidati.push_back({i,j});
            }
        }
    }
    ll sum=0;
    for (i=0; i<candidati.size(); i++)
    {
        ll ok1=1;
        for (j=1; j<=n; j++)
        {
            for (int k=j+1; k<=n; k++)
            {
                if (seinter({v[candidati[i].first],v[candidati[i].second]}, {v[j],v[k]}))
                {
                    ok1=0;
                    break;
                }
            }
            if (ok1==0)
            {
                break;
            }
        }
        sum=sum+ok1;
    }
    cout<<sum;
    return 0;
}

Compilation message

geometrija.cpp: In function 'int main()':
geometrija.cpp:131:27: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<Triangle>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  131 |             for (ll j=0; j<triunghiuri.size(); j++)
      |                          ~^~~~~~~~~~~~~~~~~~~
geometrija.cpp:153:19: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<Triangle>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  153 |     for (ll j=0; j<triunghiuri.size(); j++)
      |                  ~^~~~~~~~~~~~~~~~~~~
geometrija.cpp:169:16: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  169 |     for (i=0; i<candidati.size(); i++)
      |               ~^~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 460 KB Output is correct
2 Correct 1 ms 448 KB Output is correct
3 Correct 1 ms 460 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 456 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 332 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 460 KB Output is correct
2 Correct 1 ms 448 KB Output is correct
3 Correct 1 ms 460 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 456 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 332 KB Output is correct
12 Correct 14 ms 1336 KB Output is correct
13 Correct 12 ms 1356 KB Output is correct
14 Correct 13 ms 1220 KB Output is correct
15 Correct 10 ms 1100 KB Output is correct
16 Correct 44 ms 1304 KB Output is correct
17 Correct 39 ms 1292 KB Output is correct
18 Correct 30 ms 1228 KB Output is correct
19 Correct 24 ms 1328 KB Output is correct
20 Correct 88 ms 1484 KB Output is correct
21 Correct 90 ms 1328 KB Output is correct
22 Correct 26 ms 1228 KB Output is correct
23 Correct 25 ms 1228 KB Output is correct

Subtask #3
0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 460 KB Output is correct
2 Correct 1 ms 448 KB Output is correct
3 Correct 1 ms 460 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 456 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 332 KB Output is correct
12 Correct 14 ms 1336 KB Output is correct
13 Correct 12 ms 1356 KB Output is correct
14 Correct 13 ms 1220 KB Output is correct
15 Correct 10 ms 1100 KB Output is correct
16 Correct 44 ms 1304 KB Output is correct
17 Correct 39 ms 1292 KB Output is correct
18 Correct 30 ms 1228 KB Output is correct
19 Correct 24 ms 1328 KB Output is correct
20 Correct 88 ms 1484 KB Output is correct
21 Correct 90 ms 1328 KB Output is correct
22 Correct 26 ms 1228 KB Output is correct
23 Correct 25 ms 1228 KB Output is correct
24 Correct 440 ms 7244 KB Output is correct
25 Correct 299 ms 7244 KB Output is correct
26 Correct 489 ms 7508 KB Output is correct
27 Correct 462 ms 7284 KB Output is correct
28 Correct 506 ms 7248 KB Output is correct
29 Correct 264 ms 5836 KB Output is correct
30 Correct 304 ms 5900 KB Output is correct
31 Execution timed out 1085 ms 6348 KB Time limit exceeded
32 Halted 0 ms 0 KB -