166 Fraction to Recurring Decimal
166. Fraction to Recurring Decimal
题目: https://leetcode.com/problems/fraction-to-recurring-decima/
难度:
Medium
class Solution:
# @return a string
def fractionToDecimal(self, n, d):
res = ''
if n == 0: # zero numerator
return str(n)
if (n < 0) ^ (d < 0): # determine the sign
res += '-'
n = abs(n) # remove sign of operands
d = abs(d)
res += str(n / d) # append integral part
if (n % d == 0): # in case no fractional part
return res
res += '.'
r = n % d
m = {}
while r: # simulate the division process
if r in m: # meet a known remainder
res = res[:m[r]] + '(' + res[m[r]:] + ')' # so we reach the end of the repeating part
break
m[r] = len(res) # if the remainder is first seen, remember the current position for it
r *= 10
res += str(r / d) # append the quotient digit
r %= d
return res
