I am trying to solve the following problem, not necessarily with ppl.
Given positive integers $A0,B0,L$ find integers $A,B$ satisfying:
1 <= A A <= L 1 <= B B <= L 1 <= A0*A - B0*B A0*A - B0*B <= L
Encoded it in PPL by modifying an example (also attached): ===== Constraint_System cs; cs.insert(A >= 1); cs.insert(A <= Coefficient(L)); cs.insert(B >= 1); cs.insert(B <= Coefficient(L)); cs.insert(Coefficient(A0)*A - Coefficient(B0)*B >= 1); cs.insert(Coefficient(A0)*A - Coefficient(B0)*B <= Coefficient(L) );
// All integer variables. Variables_Set ivs(A, B);
// Cost function. Linear_Expression cost(Coefficient("10"));
MIP_Problem mip(cs.space_dimension(), cs.begin(), cs.end(), ivs, cost, MINIMIZATION);
if (mip.solve() != OPTIMIZED_MIP_PROBLEM) {
======= (reads 3 ints from stdin)
This works for small input, but for:
A0=654013667618 B0=654013667619 L=808711
PPL consumes 6GB RAM very fast and I run out of memory.
Am I doing something wrong?
Other ways to solve the problem?
Attached is the source, function "test10".
Thank you.
ppl-1.1 on x86_64 linux.