SCIP - assignment with task sizes

import { initMPSolver, MPSolver, setWorkerBridgeEnabled } from 'or-tools-wasm/mp-solver';

const costs = [
  [90, 76, 75, 70, 50, 74, 12, 68],
  [35, 85, 55, 65, 48, 101, 70, 83],
  [125, 95, 90, 105, 59, 120, 36, 73],
  [45, 110, 95, 115, 104, 83, 37, 71],
  [60, 105, 80, 75, 59, 62, 93, 88],
  [45, 65, 110, 95, 47, 31, 81, 34],
  [38, 51, 107, 41, 69, 99, 115, 48],
  [47, 85, 57, 71, 92, 77, 109, 36],
  [39, 63, 97, 49, 118, 56, 92, 61],
  [47, 101, 71, 60, 88, 109, 52, 90],
];
const taskSizes = [10, 7, 3, 12, 15, 4, 11, 5];
const totalSizeMax = 15;

setWorkerBridgeEnabled(true);
await initMPSolver();
const solver = MPSolver.CreateSolver('SCIP');
if (!solver) throw new Error('SCIP backend is unavailable');
solver.SetNumThreads(4);

const x = costs.map((row, worker) =>
  row.map((_, task) => solver.BoolVar(`x[${worker},${task}]`)));

for (let worker = 0; worker < costs.length; worker++) {
  const capacity = solver.Constraint(-solver.infinity(), totalSizeMax);
  for (let task = 0; task < taskSizes.length; task++) {
    capacity.SetCoefficient(x[worker][task], taskSizes[task]);
  }
}
for (let task = 0; task < taskSizes.length; task++) {
  const assignedOnce = solver.Constraint(1, 1);
  for (let worker = 0; worker < costs.length; worker++) {
    assignedOnce.SetCoefficient(x[worker][task], 1);
  }
}

const objective = solver.Objective();
for (let worker = 0; worker < costs.length; worker++) {
  for (let task = 0; task < taskSizes.length; task++) {
    objective.SetCoefficient(x[worker][task], costs[worker][task]);
  }
}
objective.SetMinimization();

const status = await solver.Solve();
console.log(status, objective.Value());