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1. Two Sum

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,Because nums[0] + nums[1] = 2 + 7 = 9,return [0, 1].

class Solution(object):    def twoSum(self, nums, target):        d = {}        for i, n in enumerate(nums):            sec_n = target - n            if sec_n in d:                return [d[sec_n], i]            else:                d[n] = ix =Solution()print(x.twoSum([1,1,3,4],5))

7. Reverse Integer

Given a 32-bit signed integer, reverse digits of an integer.

Example 1:

Input: 123Output:  321

Example 2:

Input: -123Output: -321

Example 3:

Input: 120Output: 21

Note:

Assume we are dealing with an environment which could only hold integers within the 32-bit signed integer range. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

class Solution:    def reverse(self, x):        """        :type x: int        :rtype: int        """        x = str(x)        if x[-1] == "0" and len(x)>1:        	x = x[:-1]        if x[0] == "-":        	res = int("-" + x[-1:0:-1])        	return res if res.bit_length() < 32 else 0        else:        	res = int(x[::-1])        	return res if res.bit_length() < 32 else 0x = Solution()print(x.reverse(0))print(x.reverse(-12030))

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