Submission #9127

#	Time	Username	Problem	Language	Result	Execution time	Memory
9127		maniac	Wall construction (kriii2_WA)	C++98	4 / 4	0 ms	1228 KiB

WA

#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
   
#define INF 1600000001
   
using namespace std;
   
typedef pair <long long, long long> ll;
ll st=ll(INF, INF);
   
int ccw(ll a, ll b, ll c){
    long long t = a.first*b.second - a.second*b.first;
    t += b.first*c.second - b.second*c.first;
    t += c.first*a.second - c.second*a.first;
    if(t>0) return 1;
    else if(t<0) return -1;
    else return 0;
}
   
bool comp(ll a, ll b){
    return ccw(st, a, b) < 0;
}
 
vector <ll> convex_hull( vector <ll> &p ){
    vector <ll> re;
    sort(p.begin(), p.end());
    st = p[0];
    stable_sort(p.begin()+1, p.end(), comp);
       
    int l=p.size();
    for(int i=0; i<l; i++){
        while(re.size()>=2 && ccw(re[re.size()-2], re[re.size()-1], p[i]) >=0 )
            re.pop_back();
        re.push_back(p[i]);
    }
    return re; 
}

double dist( ll a, ll b ){
	return sqrt( (double)(a.first-b.first)*(a.first-b.first) + (a.second-b.second)*(a.second-b.second) );
}

int main(){
    vector <ll> p;
    long long n, a, b;
	double r;
    scanf("%lld %lf", &n, &r);
    for(int i=0; i<n; i++){
        scanf("%lld %lld", &a, &b);
        p.push_back(ll(a, b));
    }
    
	vector <ll> c = convex_hull( p );
	int sz = c.size();

	double ans = 2*r*acos(-1.0);
	for(int i=0; i<sz; i++)
		ans += dist( c[i], c[(i+1)%sz] );
	

    printf("%.13f\n", ans);
}

• Subtask 1: 1 / 1
• Subtask 2: 3 / 3