如何在不使用*的情况下获得两个整数的乘积

Question

我试图找出在我的解决方案中不使用*而获得两个整数的产品的方法.我得到的最接近的是

/*Example: 2,5 output ====> 10 */
/*Example: 10,5 output ====> 50 */

const productOfTwoInt = (int,int2) => {
  var data1 = 0;
  var data2 = 0;

  var result;
  var result2;  

  for(var x = 0; x <= int; x++) {
      result = x += data1
      console.log(result)
  }

  for(var j = 0; j <= int2; j++) {
      result2 = j += data2
  }

  return result + result2    
}

console.log(productOfTwoInt(3,5))

Answer 1

你可以采取一些转移,称为古埃及乘法或俄罗斯乘法.

  a     b     p   comment
----  ----  ----  ----------------------------------
  6     8     0   skip, because a is even
  3    16    16   add 16 to p, because a is odd
  1    32    48   add 32 to p, because a is odd
  0    64    48   stop iteration, because a is zero

function product(a, b) {
    var p = 0;
    while (a) {
        p += (a & 1) && b;
        a >>= 1;
        b <<= 1;
    }
    return p;
}

console.log(product(6, 8)); // 48