Quantum Modeler · Learn
Read a QUBO
Understand a binary quadratic expression without losing its offset or counting interactions twice.
Understand
A QUBO minimizes E(x) = c + Σ aᵢxᵢ + Σᵢ<ⱼ bᵢⱼxᵢxⱼ with binary xᵢ. Each distinct pair appears once in this expression convention. The constant c changes reported energy, even though it does not change which assignment is best.
A negative linear coefficient rewards selecting a bit. A positive pair coefficient discourages selecting both bits. Constraints can contribute extra terms, so the lowest domain cost need not match the lowest energy of an invalid encoding.
Visualize
Inspect the native QUBO coefficients and recorded energies. Node labels show linear coefficients; connections show pair terms.
Loading the local example explorer…
Experiment
Compare bitstrings 000 and 010 in the recorded assignment selector. Then select the exact reference. Use the displayed coefficients to explain their different energies on paper.
Apply
Use “Try this example” to preload the expression in Custom QUBO, review it, then explicitly build it. The downloadable source preserves the expression convention. Nothing executes automatically.
Check your understanding
How often is each pair term counted in the displayed expression?