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my method is O(n*log(n)) But Wrong answer.
any one can help me!
thank you!

[cpp]
#include<iostream.h>
#include<stdio.h>
#include<math.h>

#include<fstream.h>
ifstream in("es_10245.in");
//#define in cin

const double eps=1e-14;
struct point{
double x,y;
} p[10000];
int N;


void swap(int i,int j ...

What is wrong with my program?
[cpp]
#include<iostream.h>
#include<math.h>
#include<stdio.h>

const double eps=1e-14;
double cal(double S,double D)
{
if(S>=D) return S;
double temp;
double k;
temp=floor(sqrt(2*D))+1;
for(k=temp;k>0;k--){
if(((2*S+k-1)*k<2*D)&&(2*D-(2*S+k)*(k+1)<eps)) return ...

I got wrong answer. Anyone can help me about this!
Thank you very much!
[cpp]
/*

#include<iostream.h>

#include<fstream.h>
ofstream out("es_10006.out");

int notprime[65000];
int prime[6505];
int num[100];

int cal(int a,int k,int n)
//return a^k(mod n)
{
int ans=a;
if(k==1) return a;
if(k%2 ...