[NOIP 2009][vijos 1810]ミサイル迎撃(列挙)

#include
#include
#include
#include
using namespace std;
#define N 100005
#define inf 2100000000

int n,a,b,c,d,Max,ans;
struct hp{int x,y,dis;}e[N];

int calc(int a,int b,int c,int d)
{
    return (a-c)*(a-c)+(b-d)*(b-d);
}
int cmp(hp a,hp b)
{
    return a.dis>b.dis;
}
int main()
{
    scanf("%d%d%d%d",&a,&b,&c,&d);
    scanf("%d",&n);
    for (int i=1;i<=n;++i)
    {
        scanf("%d%d",&e[i].x,&e[i].y);
        e[i].dis=calc(a,b,e[i].x,e[i].y);
    }   
    sort(e+1,e+n+1,cmp);ans=inf;
    for (int i=1;i<=n;++i)
    {
        ans=min(ans,e[i].dis+Max);
        Max=max(Max,calc(c,d,e[i].x,e[i].y));
    }
    ans=min(ans,Max);
    printf("%d
",ans);
}