beltmatic solver tool

beltmatic

function generateExpressions(target, count, maxNum) {
  const operators = ['+', '-', '*', '/'];
  let n=0;
  while (n < count) {
    const nums = [];
    const ops = [];
    let numCount = Math.floor(Math.random() * 4) + 2;

    for (let i = 0; i < numCount; i++) {
      nums.push(Math.floor(Math.random() * maxNum) + 1);
    }

    for (let i = 0; i < numCount - 1; i++) {
      ops.push(operators[Math.floor(Math.random() * 4)]);
    }

    const expression = nums.reduce((acc, num, index) => {
      return acc + num + (ops[index] || '');
    }, '');

    if (eval(expression) === target) {
      console.log(target,"=",expression);
      n++;
    }
  }
}

// 
const args = process.argv.slice(2);
const target = parseInt(args[0]);
const count = parseInt(args[1]) || 10;
const maxNum = parseInt(args[2]) || 100;

if (isNaN(target)) {
  console.error('please specify a number');
  process.exit(1);
}

generateExpressions(target, count, maxNum);

# 807:target number,  10:count, 11:max number to use.
node solve.js 807 10 11 

807 = 7+8*10*10
807 = 10*8*10+7
807 = 2+5+10*10*8
807 = 9*9*10+2-5
807 = 10*9*9-3
807 = 10*9*9-3
807 = 7+10*10*8
807 = 1-4+10*9*9
807 = 10*9*9-3
807 = 11*8*9+6+9

solve.js 1123 10 11
1123 = 3+7*10*8*2
1123 = 3*7*9*6-11
1123 = 4*7*5*8+3
1123 = 3+4*8*5*7
1123 = 3+7*10*8*2
1123 = 3+4*5*7*8
1123 = 3+4*10*7*4
1123 = 7*4*5*8+3
1123 = 3+4*10*7*4
1123 = 7*9*2*9-11