Want to get away from the circle (sort + binary search)

Title: http://www.51nod.com/onlineJudge/submitDetail.html#!judgeId=427658

First, the circle on the x-axis to the left starting point in ascending order, and then two points to find the first starting point than the end of the circle to find a large circle (that is, away)

Importjava.util.Arrays;ImportJava.util.Comparator;ImportJava.util.Scanner;classCircle {intX,r,sta,end; Circle (intXintr) { This. x=x;  This. r=R;  This. sta=x-R;  This. end=x+R; }    } Public classN1278 { Public Static voidMain (string[] args) {//TODO auto-generated Method StubScanner cin=NewScanner (system.in); intn=Cin.nextint (); Circle C[]=NewCircle[n];  for(inti=0;i<n;i++) C[i]=NewCircle (Cin.nextint (), Cin.nextint ()); Arrays.sort (c,NewComparator<circle>()        {             Public intCompare (Circle c1,circle C2) {if(c1.sta>=C2.sta)return1; Else                    return-1;        }        }); intSum=0;  for(inti=0;i<n-1;i++)        {            intp=search (i,c,n); if(P!=-1) Sum+=n-p;    } System.out.print (sum); }     Public Static intSearchintPos,circle c[],intLen) {        intKey=c[pos].end,begin=pos+1,last=len-1;  while(begin<Last ) {            intMid= (begin+last)/2; if(c[mid].sta>key) last=mid; Elsebegin=mid+1; }        if(c[begin].sta>key)returnbegin; Else            return-1; }}

Want to get away from the circle (sort + binary search)