See this code the judge says comp. error but
it is right!
/* @JUDGE_ID: 11754GA 5 C++ */
#include <iostream.h>
#include <MATH.h>
const max = 100;
typedef struct { float x; float y;} TPoint;
TPoint a[max];
int br=0,n;
void swap(TPoint& x,TPoint& y)
{
TPoint z=x; x=y; y=z;
}
void QSort(int l,int r)
{
int i=l, j=r, x=abs(a[(i+j)/2].y-a[(i+j)/2].x);
do
{
while (x>abs(a[i].y-a[i].x)) i++;
while (x<abs(a[j].y-a[j].x)) j--;
if ( i<=j) swap(a[i++],a[j--]);
} while (i<j);
if (j>l) QSort(l,j);
if (i<r) QSort(i,r);
}
void QSort2(int l,int r)
{
int i=l, j=r, x=abs(a[(i+j)/2].x);
do
{
while (x>a[i].x) i++;
while (x<a[j].x) j--;
if ( i<=j) swap(a[i++],a[j--]);
} while (i<j);
if (j>l) QSort2(l,j);
if (i<r) QSort2(i,r);
}
void InPu()
{
cin>>n;
for (int i=1;i<=n; i++)
{
int x,y;
cin>>x>>y;
if (x<y){ a[++br].x=x; a[br].y=y; }
else {a[++br].x=y; a[br].y=x; }
}
}
void DelBad1()
{
for (int i=1;i<=n; i++)
{
if (a[i].x!=1000)
for (int j=i+1; j<=n; j++)
if ( (a[j].x!=1000) && (a[j].x<a[i].x) && (a[j].y>a
[i].y) )
{ a[j].x=1000; a[j].y=1000; }
}
}
void DelBad2()
{
for (int i=1; i<=n; i++)
{
int loshi=0;
if (a[i].x!=1000)
for (int j=1; j<=n; j++)
if ( (i!=j) && (a[j].x!=1000) )
if ( ((a[i].x<a[j].x) && (a[i].y>a[j].x)) ||
((a[i].x<a[j].y) && (a[i].y>a[j].y)) )
{ loshi++; if (loshi>1) { a[i].x=1000; a[i].y=1000;
break; } }
}
}
void DelBad3()
{
for (int i=1; i<=n; i++)
{
if (a[i].x!=1000)
for (int j=1; j<=n; j++)
if ( (i!=j) && (a[j].x!=1000) )
if ( ((a[i].x<a[j].x) && (a[i].y>a[j].x)) ||
((a[i].x<a[j].y) && (a[i].y>a[j].y)) )
{ a[j].x=1000; a[j].y=1000;}
}
}
void main()
{
InPu();
QSort(1,n);
DelBad1();
QSort2(1,n);
for (int i=1; i<=n; i++)
if (a[i].x==1000) {n=i-1; break; }
DelBad2();
QSort2(1,n);
for (i=1; i<=n; i++)
if (a[i].x==1000) {n=i-1; break; }
DelBad3();
QSort2(1,n);
for (i=1; i<=n; i++)
if (a[i].x==1000) {n=i-1; break; }
cout<<n<<endl;
for (i=1; i<=n; i++)
cout<<a[i].x<<" "<<a[i].y<<endl;
}
