Submission #585061

#	Time	Username	Problem	Language	Result	Execution time	Memory
585061		hibiki	Triangles (CEOI18_tri)	C++11	Compilation error	0 ms	0 KiB

tri

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

#define pb push_back
#define sz(x) (int)x.size()

// static int N;
// static long long *x, *y;
// static int queries=0;
//
// static void init() {
// 	static int is_inited=0;
// 	if (is_inited)
// 		return;
// 	is_inited=1;
// 	assert(scanf("%d", &N)==1);
// 	x=(long long*)malloc((N+1)*sizeof(long long));
// 	y=(long long*)malloc((N+1)*sizeof(long long));
// 	for (int i=1; i<=N; i++)
// 		assert(scanf("%lld%lld", &x[i], &y[i])==2);
// }
//
// int get_n() {
// 	init();
// 	return N;
// }
//
// int is_clockwise(int a, int b, int c) {
// 	init();
// 	assert(a>=1 && a<=N);
// 	assert(b>=1 && b<=N);
// 	assert(c>=1 && c<=N);
// 	assert(a!=b && a!=c && b!=c);
// 	queries++;
//         if(queries == 1000 * 1000 + 1)
//             printf("Too many queries!");
// 	return (x[b]-x[a])*(y[c]-y[a])-(x[c]-x[a])*(y[b]-y[a])<0;
// }
//
// void give_answer(int s) {
// 	init();
// 	printf("%d\n", s);
// }

int n, cnt = 0, st;
vector<int> v, stk1, stk2;



int main()
{
    n = get_n();
    v.pb(1);
    v.pb(2);
    for(int i = 3; i <= n; i++)
    {
        while(sz(v) > 1 && is_clockwise(v[sz(v) - 2], v[sz(v) - 1], i))
            v.pop_back();
        v.pb(i);
    }
    cnt = 1;
    st = v[1];
    int lst = v[1];
    while(1)
    {
        for(int i = 1; i <= n; i++)
        {
            if(i == lst) continue;
            bool ok = true;
            for(int j = 1; j <= n; j++)
            {
                if(j == i || j == lst) continue;
                if(!is_clockwise(lst, i, j))
                {
                    ok = false;
                    break;
                }
            }
            if(ok)
            {
                // printf("%d %d\n",lst,i);
                if(i == st)
                {
                    give_answer(cnt);
                    return 0;
                }
                cnt++;
                lst = i;
                break;
            }
        }
    }
    return 0;
}

Compilation message (stderr)

tri.cpp: In function 'int main()':
tri.cpp:52:9: error: 'get_n' was not declared in this scope
   52 |     n = get_n();
      |         ^~~~~
tri.cpp:57:28: error: 'is_clockwise' was not declared in this scope
   57 |         while(sz(v) > 1 && is_clockwise(v[sz(v) - 2], v[sz(v) - 1], i))
      |                            ^~~~~~~~~~~~
tri.cpp:73:21: error: 'is_clockwise' was not declared in this scope
   73 |                 if(!is_clockwise(lst, i, j))
      |                     ^~~~~~~~~~~~
tri.cpp:84:21: error: 'give_answer' was not declared in this scope
   84 |                     give_answer(cnt);
      |                     ^~~~~~~~~~~