1 #include <iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #include<stdlib.h> 6 #include<vector> 7 #include<cmath> 8 #include<queue> 9 #include<set>10 using namespace std;11 #define N 101012 #define LL long long13 #define INF 0xfffffff14 const double eps = 1e-8;15 const double pi = acos(-1.0);16 const double inf = ~0u>>2;17 struct point18 {19     double x,y,r;20     point(double x=0,double y=0,double r =0):x(x),y(y),r(r){}21 }p[N];22 int o[N];23 bool f[N];24 typedef point pointt;25 pointt operator -(point a,point b)26 {27     return point(a.x-b.x,a.y-b.y);28 }29 int dcmp(double x)30 {31     if(fabs(x)<eps) return 0;32     return x<0?-1:1;33 }34 double dis(point a)35 {36     return sqrt(a.x*a.x+a.y*a.y);37 }38 int main()39 {40     int n,i,j;41     while(scanf("%d",&n)!=EOF)42     {43         memset(f,0,sizeof(f));44         for(i = 1; i <=  n; i++)45         scanf("%lf",&p[i].r);46         p[1] = point(p[1].r,0,p[1].r);47         p[0].r = p[0].x = 0;48         double rig;49         for(i = 2; i <= n; i++)50         {51             double maxz = 0;52             int x = i-1;53             for(j = i-1 ; j >= 1 ; j--)54             {55                 double d = sqrt((p[j].r+p[i].r)*(p[j].r+p[i].r)-(p[j].r-p[i].r)*(p[j].r-p[i].r))+p[j].x;56                 if(dcmp(d-maxz)>=0)57                 {58                     maxz = max(maxz,d);59                     x = j;60                 }61             }62             if(dcmp(maxz-p[i].r)<=0)63             {64                 p[i].x = p[i].r;65                 for(j = 1 ; j < i; j++)66                 f[j] = 1;67                 continue;68             }69             p[i].x = maxz;70             //cout<<i<<" "<<x<<" "<<maxz<<endl;71             for(j = x+1 ; j < i; j++)72             f[j] = 1;73         }74         int x = n;75         for(i = 1; i <= n ;i ++)76         {77             if(dcmp(p[i].r+p[i].x-rig)>0)78             {79                 rig = max(rig,p[i].r+p[i].x);80                 x = i;81             }82         }83         for(i = x+1 ; i <= n ;i++)84         f[i] = 1;85         int g = 0;86         for(i = 1; i <= n ;i++)87         if(f[i])88         o[++g] = i;89         cout<<g<<endl;90         for(i = 1; i <= g ;i++)91         cout<<o[i]<<endl;92     }93     return 0;94 }