IITWPC4C-Maggu and Vectors

Maggu and Vectors

below given code is for iitwpc4c spoj or maggu and vectors spoj.

for first time i get approximately 20 WA in this problem . here in this problem we have to check only that vector can form triangle or not.

#include <iostream>
#include <stdio.h>
#include <cmath>
#include <cstdlib>
using namespace std;
class vect
{
public:
 int x,y;
 vect operator +(vect v)
 {
  vect temp;
  temp.x=v.x + x;
  temp.y=v.y + y;
  return temp;
 }
 vect operator -()
 {
  vect temp;
  temp.x = -1*x;
  temp.y = -1*y;
  return temp;
 }
 bool operator ==(vect v)
 {
  if(v.x==x && v.y == y)
   return true;
  else 
   return false;
 }
 bool operator !=(vect v)
 {
  if(v.x != x || v.y != y)
   return true;
  else 
   return false;
 }
 bool is_colinear(vect v)
 {
  if(x==v.x||y==v.y)
         return 1;
     else if(x==0&&y==0)
         return 1;
     else if(v.x==0&&v.y==0)
         return 1;
     else if(y==0)
         return 0;
     else if(v.y==0)
          return 0;
      else if(x/(double)v.x==y/(double)v.y)
          return 1;
     else
         return 0;
 }
 vect make_pair()
 {
  vect temp;
  if(x<0)
   temp.x=1001 + (-1*x);
  else 
   temp.x=x;
  if(y<0)
   temp.y=1001 + (-1 * y);
  else
   temp.y=y;
  return temp;
 }
};
int check[2009][2009]={0};
int main()
{
 int t;
 scanf("%d",&t);
 while(t--)
 {
  int n,i,j,k,flag=0,pos_y,pos_x,x2,y2;
  vect v[1009],temp;
  for(i=0;i<2003;i++)
   for(j=0;j<=2003;j++)
    check[i][j]=0;
  scanf("%d",&n);
  for(i=0;i<n;i++){
   scanf("%d%d",&v[i].x,&v[i].y);
   if(v[i].x<0){
    pos_x=1001 + (-1*v[i].x);
   }
   else {
    pos_x=v[i].x;}
   if(v[i].y<0){
    pos_y=1001 + (-1 * v[i].y);}
   else{
    pos_y=v[i].y;   }
   check[pos_y][pos_x]=1;
  }
  vect zero,pos;
  zero.x=0;
  zero.y=0;
  if(n<3)
  {
   printf("NO\n");
   continue;
  }
  flag=0;
  for(i=0;i<n;i++)
  {
   for(j=i+1;j<n;j++)
   {
    if(v[i].is_colinear(v[j]))
     continue;
    temp= v[i] + v[j];
    if(temp.x<=1000 && temp.x>=-1000 && temp.y<=1000 && temp.y>=-1000)
    { 
     pos=temp.make_pair();
     if(check[pos.y][pos.x])
     {
      flag=1;
      break;
     }
    }
    temp= v[i] + (-v[j]);
    if(temp.x<=1000 && temp.x>=-1000 && temp.y<=1000 && temp.y>=-1000)
    { 
     pos=temp.make_pair();
     if(check[pos.y][pos.x])
     {
      flag=1;
      break;
     }
    }
    temp= (-v[i]) + (-v[j]);
    if(temp.x<=1000 && temp.x>=-1000 && temp.y<=1000 && temp.y>=-1000)
    { 
     pos=temp.make_pair();
     if(check[pos.y][pos.x])
     {
      flag=1;
      break;
     }
    }
    temp= (-v[i]) + v[j];
    if(temp.x<=1000 && temp.x>=-1000 && temp.y<=1000 && temp.y>=-1000)
    { 
     pos=temp.make_pair();
     if(check[pos.y][pos.x])
     {
      flag=1;
      break;
     }
    }
   }
   if(flag)
    break;
  }
  if(!flag)
   printf("NO\n");
  else 
   printf("YES\n");
 }
 return 0;
}