The closest point on the P1257 plane is close to the P1257 plane.

The closest point on the P1257 plane is close to the P1257 plane.
Description

Given n points on the plane, find the distance between a pair of points, so that the distance is the smallest among all the points of the n points.

Input/Output Format Input Format:

Row 1: n; 2 ≤ n ≤ 200000

Next n rows: each row has two real numbers: x y, which indicate the row coordinates and column coordinates of a point, separated by a space in the middle.

Output Format:

Only one row, a real number, indicates the shortest distance, accurate to four digits after the decimal point.

Input and Output sample Input example #1:

31 11 22 2

Output sample #1:

1.0000

Description

0 <= x, y <= 10 ^ 9

 

Violent water...

 

 1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<cmath> 5 #include<cstdlib> 6 using namespace std; 7 const int MAXN=10001; 8 void read(int & n) 9 {10     char c='+';int x=0;11     while(c<'0'||c>'9')c=getchar();12     while(c>='0'&&c<='9')13     {14         x=x*10+(c-48);15         c=getchar();16     }17     n=x;18 }19 int n;20 struct node21 {22     int x;23     int y;24 }a[MAXN];25 double ans=12700000;26 int main()27 {28     read(n);29     for(int i=1;i<=n;i++)30     {31         read(a[i].x);32         read(a[i].y);33     }34     for(int i=1;i<=n;i++)35     {36         for(int j=i+1;j<=n;j++)37         {38                 double p=sqrt((fabs(a[j].x-a[i].x)*fabs(a[j].x-a[i].x))+(fabs(a[j].y-a[i].y)*fabs(a[j].y-a[i].y)));39                 if(p<ans)40                 ans=p;41         }42     }43     printf("%.4lf",ans);44     return 0;45 }