oj.uz

Submission #483711

# Submission time Handle Problem Language Result Execution time Memory
483711 2021-11-01T00:04:11 Z sam571128 Geometrija (COCI21_geometrija) C++17
20 / 110
 1000 ms 1584 KB 
#include <bits/stdc++.h>

#define int long long
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

using namespace std;

typedef pair<int,int> point;
#define x first
#define y second

int operator^(point a, point b){
    return a.x*b.y-a.y*b.x;
}

int operator*(point a, point b){
    return a.x*b.x+a.y*b.y;
}

point operator-(point a, point b){
    return {a.x-b.x,a.y-b.y};
}

point operator+(point a, point b){
    return {a.x+b.x,a.y+b.y};
}

int ori(point a, point b, point c){
    int tmp = (b-a)^(c-a);
    if(tmp == 0) return 0;
    return abs(tmp)/tmp;
}
int intersect(point a, point b, point c, point d){
    int abc = ori(a,b,c);
    int abd = ori(a,b,d);
    int cda = ori(c,d,a);
    int cdb = ori(c,d,b);

    if(abc*abd < 0 && cda*cdb < 0) return true;
    else return false;
}

signed main(){
    fastio
    
    int n;
    cin >> n;
    vector<point> arr;
    for(int i = 0;i < n;i++){
        int a,b;
        cin >> a >> b;
        arr.push_back({a,b});
    }

    int ans = n*(n-1)/2;
    map<point,int> m;
    for(int a = 0; a < n; a++){
        for(int b = a+1; b < n; b++){
            for(int c = 0; c < n; c++){
                for(int d = c+1; d < n; d++){
                    if(intersect(arr[a],arr[b],arr[c],arr[d])){
                        m[{a,b}]++;
                        m[{c,d}]++;
                    }
                }
            }
        }
    }
    cout << ans-m.size() << "\n";
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 320 KB Output is correct
2 Correct 15 ms 356 KB Output is correct
3 Correct 15 ms 356 KB Output is correct
4 Correct 9 ms 308 KB Output is correct
5 Correct 10 ms 332 KB Output is correct
6 Correct 7 ms 332 KB Output is correct
7 Correct 18 ms 352 KB Output is correct
8 Correct 19 ms 360 KB Output is correct
9 Correct 14 ms 356 KB Output is correct
10 Correct 14 ms 332 KB Output is correct
11 Correct 0 ms 216 KB Output is correct

Subtask #2
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 320 KB Output is correct
2 Correct 15 ms 356 KB Output is correct
3 Correct 15 ms 356 KB Output is correct
4 Correct 9 ms 308 KB Output is correct
5 Correct 10 ms 332 KB Output is correct
6 Correct 7 ms 332 KB Output is correct
7 Correct 18 ms 352 KB Output is correct
8 Correct 19 ms 360 KB Output is correct
9 Correct 14 ms 356 KB Output is correct
10 Correct 14 ms 332 KB Output is correct
11 Correct 0 ms 216 KB Output is correct
12 Execution timed out 1088 ms 1584 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #3
0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 320 KB Output is correct
2 Correct 15 ms 356 KB Output is correct
3 Correct 15 ms 356 KB Output is correct
4 Correct 9 ms 308 KB Output is correct
5 Correct 10 ms 332 KB Output is correct
6 Correct 7 ms 332 KB Output is correct
7 Correct 18 ms 352 KB Output is correct
8 Correct 19 ms 360 KB Output is correct
9 Correct 14 ms 356 KB Output is correct
10 Correct 14 ms 332 KB Output is correct
11 Correct 0 ms 216 KB Output is correct
12 Execution timed out 1088 ms 1584 KB Time limit exceeded
13 Halted 0 ms 0 KB -