[筆記/Leetcode in Python] 1, 7, 9
July 18, 2019 | 2 Minute Read |
Tags :
Leetcode
LeetCode in Python 1. Two Sum
【法1】較慢
class Solution:
def twoSum(self, nums, target):
for i in nums:
j = target - i
start_index = nums.index(i)
next_index = start_index + 1
temp_nums = nums[next_index: ]
if j in temp_nums:
return(nums.index(i), next_index + temp_nums.index(j))
【法2】較快
class Solution:
def twoSum(self, nums, target):
dict = {}
for i in range(len(nums)):
if target - nums[i] not in dict:
dict[nums[i]] = i
else:
return [dict[target-nums[i]], i]
LeetCode in Python 7. Reverse Integer
- Note:
- 拿掉註解可以跑比較快。
a//10 比 int(a/10) 快。
class Solution:
def reverse(self, x):
num = 0
a = abs(x) #取絕對值
while(a != 0):
temp = a % 10
num = num * 10 + temp
a = a // 10
if x > 0 and num < 2147483647:
return num
elif x < 0 and num <= 2147483647:
return -num
else:
return 0
LeetCode in Python 9. Palindrome Number
class Solution:
def isPalindrom(self, x):
num = 0
a = abs(x)
while(a != 0):
temp = a % 10
num = num * 10 + temp
a = a // 10
if x >= 0 and x == num:
return True
else:
return False