Divide Two Integers


#1

Given two integers dividend and divisor, divide two integers without using multiplication, division and mod operator.

Return the quotient after dividing dividend by divisor.

The integer division should truncate toward zero.

Example 1:

Input: dividend = 10, divisor = 3
Output: 3

Example 2:

Input: dividend = 7, divisor = -3
Output: -2

Note:

  • Both dividend and divisor will be 32-bit signed integers.
  • The divisor will never be 0.
  • Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231,  231 − 1]. For the purpose of this problem, assume that your function returns 231 − 1 when the division result overflows.

#2

The question asks not to use Divison or Multiplication, but doesn’t mention substraction, so we use that.

import "math"

func divide(dividend int, divisor int) int {
    quotient := 0
    sign := 1
   
    // takes care of overflow
    if dividend == math.MinInt32 && divisor == -1 {
         return math.MaxInt32
    }
           

    // capture the sign
    if divisor < 0 && dividend < 0{
      divisor = -1 * divisor
      dividend = -1 * dividend
    } else if divisor < 0{
        divisor = -1 * divisor
        sign = -1
    } else if dividend < 0{
        dividend = -1 * dividend
        sign = -1
    }
   
   //  uses substraction instead of shift operators
    for dividend >= divisor {
        dividend -= divisor
        quotient++
    }
    
    return sign*quotient
}