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About

Satisfyer is a Deno module that allows you to solve a so-called Constraint-Satisfaction-Problem (CSP). This module includes several solvers to fit your use case.

  • Brute-Force-Solver
  • Backtrack-Solver
  • Constraint-Propagation-Solver

Example

Import the solver function from mod.ts and define your problem using the CSP type. The solver takes a CSP and optionally a solver of your choice as parameters, by default the constraint-propagation method will be used. A CSP is constructed using a dictionary with variables, values and constraints as keys, and its corresponding values as a set of strings. Values can also be defined as a set of numbers.
The solver takes the CSP as a parameter and returns the solution.

8-Queens-Problem as CSP and calling the solver:

import { CSP, solve } from "https://deno.land/x/satisfyer/mod.ts";

//Defining variables, values and constraints using loops
const variables = new Set(Array.from({ length: 8 }, (_, i) => `V${i + 1}`));
const values = new Set(Array.from({ length: 8 }, (_, i) => i + 1));
const constraints = new Set<string>();
//adding constraints
for (let i = 1; i <= 8; i++) {
  for (let j = 1; j <= 8; j++) {
    if (i < j) {
      constraints.add(`V${i} != V${j}`);
      constraints.add(
        `Math.abs(V${j} - V${i}) != ${j - i}`,
      );
    }
  }
}

//The CSP
const csp: CSP = {
  variables: variables,
  values: values,
  constraints: constraints,
};

// const solution = solve(csp);
const solution = solve(csp, "bruteforce");
console.log(solution);