bzoj1007

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<cmath>
 4 #include<ctime>
 5 #include<cstdlib>
 6 #include<iostream>
 7 #include<algorithm>
 8 #define rep(i,l,r) for(int i=l;i<(r);i++)
 9 #define clr(a,x) memset(a,x,sizeof(a))
10 using namespace std;
11 typedef long long ll;
12 const int maxn=50009;
13 struct line{
14     int p;
15     double a,b;
16     inline bool operator<(const line&A)const{
17         return a<A.a||(a==A.a&&b>A.b);
18     }
19 };
20 int n,top=0,S[maxn];
21 line x[maxn];
22 bool p[maxn];
23 double cross(int a,int b){
24     return (x[b].b-x[a].b)/(x[a].a-x[b].a);
25 }
26 int main(){
27     scanf("%d",&n);
28     rep(i,1,n+1) scanf("%lf%lf",&x[i].a,&x[i].b),x[i].p=i;
29     sort(x+1,x+n+1);
30     rep(i,1,n+1){
31         if(i>1&&x[i].a==x[i-1].a) continue;
32         while(top>1&&cross(S[top-1],S[top])>=cross(S[top],i)) S[top--]=0;
33         S[++top]=i;
34     }
35     rep(i,1,top+1) p[x[S[i]].p]=1;
36     rep(i,1,n+1) if(p[i]) printf("%d ",i);putchar(‘\n‘);
37     return 0;
38 }