29. Divide Two Integers
Given two integers
dividendanddivisor, divide two integers without using multiplication, division, and mod operator.The integer division should truncate toward zero, which means losing its fractional part. For example,
8.345would be truncated to8, and-2.7335would be truncated to-2.Return the quotient after dividing
dividendbydivisor.Note: Assume we are dealing with an environment that could only store integers within the 32-bit signed integer range:
[−231, 231 − 1]. For this problem, if the quotient is strictly greater than231 - 1, then return231 - 1, and if the quotient is strictly less than-231, then return-231.Example 1:
Input: dividend = 10, divisor = 3
Output: 3
Explanation: 10/3 = 3.33333.. which is truncated to 3.Example 2:
Input: dividend = 7, divisor = -3
Output: -2
Explanation: 7/-3 = -2.33333.. which is truncated to -2.
def divide(self, dividend: int, divisor: int) -> int:
if dividend == divisor:
return 1
if dividend == -2**31 and divisor == -1:
return (2**31) - 1
if divisor == 1:
return dividend
sign = -1 if (dividend < 0) ^ (divisor < 0) else 1
n, d = abs(dividend), abs(divisor)
ans = 0
while n >= d:
p = 0
while n >= (d << p):
p += 1
p -= 1
n -= (d << p)
ans += (1 << p)
return min(max(sign * ans, -2**31), 2**31 - 1)