Code:
#include <iostream>
#include <math.h>
#include <string>
#include <cstdlib>

using namespace std;
long tot, tsol;

int P[8][6];
int A[8][1];

template <typename T> int sgn(T val) {
return (T(0) < val) - (val < T(0));
}


int CheckIntersection(int pia, int pa, int pib, int pb) {
return abs(sgn<int>(P[A[pia][0]][pa+A[pia][1]] + P[A[pib][0]][pb+A[pib][1]]));
}

void PrintSolution() {
tsol = tsol + 1;
string c = "";
for (int z=0;z<=8;z++) {
c = c + (char)(A[z][0] + 64) + (char)(A[z][1] + 97);
}
cout << c << " ";
cout << tot;
cout << "\n";
}

int CheckPoss (int u) {
tot = tot + 1;
int f = 0;
int ret ;
switch (u) {
case 0:
f = 0;
case 1:
f = f + CheckIntersection(0,2,1,0); //'A
break;
case 2:
f = f + CheckIntersection(0,2,1,0); // 'A
f = f + CheckIntersection(1,2,2,0); // 'B
break;
case 3:
f = f + CheckIntersection(0,2,1,0) ; // 'A
f = f + CheckIntersection(1,2,2,0) ; // 'B
f = f + CheckIntersection(0,3,3,1) ; // 'C
break;
case 4:
f = f + CheckIntersection(0,2,1,0) ; // 'A
f = f + CheckIntersection(1,2,2,0) ; // 'B
f = f + CheckIntersection(0,3,3,1) ; // 'C
f = f + CheckIntersection(1,3,4,1) ; // 'D
f = f + CheckIntersection(3,2,4,0) ; // 'F
break;
case 5:
f = f + CheckIntersection(0,2,1,0) ; // 'A
f = f + CheckIntersection(1,2,2,0) ; // 'B
f = f + CheckIntersection(0,3,3,1) ; // 'C
f = f + CheckIntersection(1,3,4,1) ; // 'D
f = f + CheckIntersection(2,3,5,1) ; // 'E
f = f + CheckIntersection(3,2,4,0) ; // 'F
f = f + CheckIntersection(4,2,5,0) ; // 'G
break;
case 6:
f = f + CheckIntersection(0,2,1,0) ; // 'A
f = f + CheckIntersection(1,2,2,0) ; // 'B
f = f + CheckIntersection(0,3,3,1) ; // 'C
f = f + CheckIntersection(1,3,4,1) ; // 'D
f = f + CheckIntersection(2,3,5,1) ; // 'E
f = f + CheckIntersection(3,2,4,0) ; // 'F
f = f + CheckIntersection(4,2,5,0) ; // 'G
f = f + CheckIntersection(3,3,6,1) ; // 'H
break;
case 7:
f = f + CheckIntersection(0,2,1,0) ; // 'A
f = f + CheckIntersection(1,2,2,0) ; // 'B
f = f + CheckIntersection(0,3,3,1) ; // 'C
f = f + CheckIntersection(1,3,4,1) ; // 'D
f = f + CheckIntersection(2,3,5,1) ; // 'E
f = f + CheckIntersection(3,2,4,0) ; // 'F
f = f + CheckIntersection(4,2,5,0) ; // 'G
f = f + CheckIntersection(3,3,6,1) ; // 'H
f = f + CheckIntersection(4,3,7,1) ; // 'I
f = f + CheckIntersection(6,2,7,0) ; // 'K
break;
case 8:
f = f + CheckIntersection(0,2,1,0) ; // 'A
f = f + CheckIntersection(1,2,2,0) ; // 'B
f = f + CheckIntersection(0,3,3,1) ; // 'C
f = f + CheckIntersection(1,3,4,1) ; // 'D
f = f + CheckIntersection(2,3,5,1) ; // 'E
f = f + CheckIntersection(3,2,4,0) ; // 'F
f = f + CheckIntersection(4,2,5,0) ; // 'G
f = f + CheckIntersection(3,3,6,1) ; // 'H
f = f + CheckIntersection(4,3,7,1) ; // 'I
f = f + CheckIntersection(5,3,8,1) ; // 'J
f = f + CheckIntersection(6,2,7,0) ; // 'K
f = f + CheckIntersection(7,2,8,0) ; // 'L
break;
}

if (f == 0) {
ret = 1;
if (u == 8) {
PrintSolution();
}
}

//cout << " {f} = " << f << " {u} " << u << endl;

if (f != 0) {
ret = 0;
}
return ret;
}

void Recurse(int n) {
int m = n + 1;

//cout << "DEBUG: " << m << endl;

for (int k=0;k<=8;k++) {
int f = 0;

for(int z=0;z<=n-1;z++) {
if (A[z][0] == k) {
f = 1;
}
}

//cout << "DEBUG3 f = " << f << endl;
if(f == 0) {
for (int r=0;r<=3;r++) {
A[n][0] = k;
A[n][1] = r;
int i = CheckPoss(m);
//cout << "DEBUG2: m = " << m << " i = " << i << endl;
if ((m < 9) && (i == 1)) {
//cout << "should call recurse.. " << endl;
Recurse(m);
}
}
}
}
}

void SetPiece(int n, int A, int b, int c, int d) {
P[n][0] = A; // C/C++ indexes start from 0
P[n][1] = b;
P[n][2] = c;
P[n][3] = d;

P[n][4] = A;
P[n][5] = b;
P[n][6] = c;
}

int main () {
SetPiece(0, -3, -2, 3, 1);
SetPiece(1, 2, 1, -4, -2);
SetPiece(2, 4, 2, -3, -2);
SetPiece(3, -1, 1, 4, -4);
SetPiece(4, -4, 4, 2, -1);
SetPiece(5, 1, -1, -2, 2);
SetPiece(6, 3, 1, -2, -1);
SetPiece(7, -3, -4, 2, 3);
SetPiece(8, -4, 3, 3, -2);

Recurse(0);

long tp = pow(4.0,9)*9*8*7*6*5*4*3*2;
cout << tot << " possibilities checked." << endl;
cout << ((tp-tot)/1000000) << " million possibilities discarded." << endl;
cout << tsol << " solutions found." <<endl;
}
This is the c++ code written by me for the BASIC program present in THIS LINK : http://nrich.maths.org/1388.
Could anyone please find the bug in my code.

Regards,
Navy.